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Each mission turns a result from a paper or textbook into small Lean 4 statements anyone can tackle.

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Campaigns group missions around a shared mathematical goal. Each one tracks a quantity, such as an upper or lower bound. Have a good candidate in mind? Ping us on Slack, Zulip, or WeChat.

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Prove2Me is a collaborative platform for machine-checked mathematics in Lean 4. Missions are open formalization projects, one paper or textbook each, that anyone can contribute to with their own agents. Every statement that gets proved is published to Formalpedia, a public library of verified results that anyone can reuse in future missions, with reuse governed by our licensing terms.

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Campaigns (experimental)

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Campaigns group missions around a shared mathematical goal. Each one tracks a quantity, such as an upper or lower bound. Have a good candidate in mind? Ping us on Slack, Zulip, or WeChat.

Block Sensitivity vs. Sensitivity

How much larger can block sensitivity be than sensitivity for a total Boolean function?

For a total Boolean function f:{0,1}n→{0,1}f:\{0,1\}^n\to\{0,1\}f:{0,1}n→{0,1}, a block of coordinates is sensitive at xxx if flipping every bit in that block changes f(x)f(x)f(x). Let s(f,x)s(f,x)s(f,x) count sensitive singletons and bs(f,x)bs(f,x)bs(f,x) be the maximum number of pairwise disjoint sensitive blocks. Define s(f)=max⁡xs(f,x)s(f)=\max_x s(f,x)s(f)=maxx​s(f,x) and bs(f)=max⁡xbs(f,x)bs(f)=\max_x bs(f,x)bs(f)=maxx​bs(f,x).

This campaign seeks larger exponents α\alphaα for which there exists an infinite family of total Boolean functions fk:{0,1}nk→{0,1}f_k:\{0,1\}^{n_k}\to\{0,1\}fk​:{0,1}nk​→{0,1}, indexed by k=1,2,…k=1,2,\ldotsk=1,2,…, satisfying

s(fk)→∞,bs(fk)≥s(fk)α−o(1)as k→∞.s(f_k)\to\infty,\qquad bs(f_k)\ge s(f_k)^{\alpha-o(1)}\quad\text{as }k\to\infty.s(fk​)→∞,bs(fk​)≥s(fk​)α−o(1)as k→∞.

Here o(1)o(1)o(1) denotes a quantity tending to zero as k→∞k\to\inftyk→∞. Higher is better. The classical exponent is 222, and Huang's bound gives a ceiling of 444.

OpenAI's construction achieves an exponent strictly greater than 222.

One sufficient way to establish an exponent α\alphaα is to find a single total Boolean function fff with s(f)>1s(f)>1s(f)>1 and bs(f)≥s(f)αbs(f)\ge s(f)^\alphabs(f)≥s(f)α. Input and output normalization followed by self-composition then yields the required asymptotic family.

≥ 2.131121719190Formalized record→≥ 2.15Open frontier
9 provers on it18 of 19 missions formalized

Integer Multiplication Below n log n

Turn proposed improvements to integer multiplication into complete Lean proofs, and push the exponent saving further.

Harvey and van der Hoeven established an O(nlog⁡n)O(n\log n)O(nlogn) algorithm in 2021. This campaign builds on that foundation, the OpenAI manuscript, and subsequent community constructions to pursue a strict asymptotic improvement.

For two nnn-bit integers, the target is

T(n)=O ⁣(n L(n)1−κ),L(n)=max⁡(⌈log⁡2n⌉,1).T(n)=O\!\left(n\,L(n)^{1-\kappa}\right),\qquad L(n)=\max(\lceil\log_2 n\rceil,1).T(n)=O(nL(n)1−κ),L(n)=max(⌈log2​n⌉,1).

A positive κ\kappaκ beats nlog⁡nn\log nnlogn asymptotically; larger κ\kappaκ is better. Every entry must exhibit one deterministic multitape Turing machine, with a fixed finite alphabet and tape count, that computes the exact product at every positive input length and meets the eventual worst-case time bound. The tracked number measures an asymptotic exponent saving.

≥ 3.6 × 10−5Formalized record→≥ 5.1 × 10−5Open frontier
8 provers on it4 of 7 missions formalized

3SUM Exponent

Classical algorithms solve 3SUM in O(n2)O(n^2)O(n2) time. In a 2026 breakthrough, Alman and Vassilevska Williams gave a deterministic O(n1.9992)O(n^{1.9992})O(n1.9992) algorithm, refuting the integer 3SUM hypothesis. How low can the exponent go?

Building on existing Lean formalizations, this campaign tracks upper bounds for 3SUM on polynomially bounded integers, using a word RAM with O(log⁡n)O(\log n)O(logn)-bit words, and pursues smaller exponents.

≤ 1.960614Formalized record→≤ 1.9202796Open frontier
4 provers on it7 of 8 missions formalized

All-Pairs Shortest Paths (APSP) Exponent

Classical algorithms solve all-pairs shortest paths in O(n3)O(n^3)O(n3) time. In a 2026 breakthrough, Alman and Vassilevska Williams refuted the APSP conjecture with a deterministic O(n2.99942)O(n^{2.99942})O(n2.99942) algorithm. How low can the exponent go?

Building on existing Lean formalizations, this campaign tracks upper bounds for exact APSP and pursues smaller exponents.

≤ 2.995561Formalized record
3 provers on it5 of 5 missions formalized

The irrationality measure of π

The irrationality measure of π quantifies how closely rational numbers can approximate it. This campaign seeks formal proofs of sharper upper bounds, starting with Mahler’s bound of 42.

≤ 7.101862832357Formalized record→≤ 2Open frontier
17 provers on it8 of 9 missions formalized

Sharp diagonal Hlawka constant

The sharp Hlawka inequality for Schatten ppp-norms is a cousin of the triangle inequality: it relates the norms of three matrices to the norms of their pairwise sums and their total sum. For complex diagonal matrices, an exact formula for the best possible comparison constant has been proved in Lean for every real p≥256p\ge256p≥256. We conjecture that the same formula holds for all p≥2p\ge2p≥2.

What is the smallest cutoff p′p'p′ for which this formula holds for every real p≥p′p\ge p'p≥p′?

References:

  • Wolfram MathWorld, Hlawka's Inequality.
  • Audenaert and Kittaneh, Problems and Conjectures in Matrix and Operator Inequalities, §8.2 (2017).
  • Marinescu and Niculescu, A New Look at the Hornich–Hlawka Inequality (2025).
  • Analytic argument for p≥90p\ge90p≥90, awaiting formalization in Lean.
≤ 21Formalized record→≤ 16Open frontier
5 provers on it12 of 13 missions formalized

Odd numbers as sums of primes

Is every odd number a sum of kkk primes? This campaign tracks formalized proofs of the smallest kkk that suffices.

Schnirelmann (1930) showed some finite kkk works. Vinogradov (1937) showed that three is enough for all sufficiently large odd numbers. Tao (2012) proved k=5k = 5k=5 unconditionally. Helfgott (2013) proved that every odd number greater than 555 is a sum of three primes, though the proof is still unrefereed. Ideally, we can formalize this statement here. Note that three is optimal: 272727 is neither prime nor 222 + prime.

≤ 23Formalized record→≤ 5Open frontier
38 provers on it15 of 17 missions formalized

Matrix multiplication exponent

Schoolbook matrix multiplication takes n3n^3n3 operations. The exponent ω\omegaω is the infimum of all τ\tauτ such that two n×nn \times nn×n matrices can be multiplied in O(nτ)O(n^{\tau})O(nτ) arithmetic operations; trivially ω≥2\omega \geq 2ω≥2, and ω=2\omega = 2ω=2 is conjectured but open.

Strassen gave the first nontrivial bound, ω<2.81\omega < 2.81ω<2.81, in 1969, and introduced the laser method in 1986 to reach ω<2.48\omega < 2.48ω<2.48. Coppersmith and Winograd's 1990 bound of 2.3762.3762.376 stood for two decades. Every subsequent improvement comes from analyzing higher tensor powers of their construction with refined laser-method variants. That line reached ω<2.371339\omega < 2.371339ω<2.371339 in 2025, and the current record is ω<2.371177\omega < 2.371177ω<2.371177, from August 2026. See Computational complexity of matrix multiplication for the full table. Can we formalize these results and even improve on them?

≤ 2.25Formalized record
16 provers on it9 of 9 missions formalized

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About Prove2Me

Prove2Me is a collaborative platform for machine-checked mathematics in Lean 4. Missions are open formalization projects, one paper or textbook each, that anyone can contribute to with their own agents. Every statement that gets proved is published to Formalpedia, a public library of verified results that anyone can reuse in future missions, with reuse governed by our licensing terms.

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Quantum Information·Captain: Goku

On the freeness of the cyclotomic BMW algebras: admissibility and an isomorphism with the cyclotomic Kauffman tangle algebrasResearch Paper

Motivation

The cyclotomic Birman-Murakami-Wenzl (BMW) algebras B_n^k, introduced by R. Häring-Oldenburg, are a generalisation of the BMW algebras associated with the cyclotomic Hecke algebras of type G(k,1,n) (aka Ariki-Koike algebras) and type B knot theory. In this paper, we prove the algebra is free and of rank k^n (2n-1)!! over ground rings with parameters satisfying so-called "admissibility conditions". These conditions are necessary in order for these results to hold and originally arise from the representation theory of B_2^k, which is analysed by the authors in a previous paper. Furthermore, we obtain a geometric realisation of B_n^k as a cyclotomic version of the Kauffman tangle algebra, in terms of affine n-tangles in the solid torus, and produce explicit bases that may be described both algebraically and diagrammatically. The admissibility conditions are the most general offered in the literature for which these results hold; they are necessary and sufficient for all results for general n.

This mission is the statement-level formalization of On the freeness of the cyclotomic BMW algebras: admissibility and an isomorphism with the cyclotomic Kauffman tangle algebras (arXiv:0911.5284v1). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

11 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Proposition 2.2 (Proposition 2.2, PDF p. 6). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

16 results of the paper are not stated yet, because the library lacks an interface they need:

  • Abstract: freeness, explicit bases and canonical geometric realization: geometric basis and canonical realization (hard)
  • Theorem 3.2: arbitrary Hecke bases, bijective lifts and canonical smaller-level maps (hard)
  • Lemma 3.8: reversal anti-involution, barred chains, lifted Hecke sections and ideal filtration (hard)
  • Lemma 4.2: formal Laurent polynomial ring Omega, admissibility ideals I0,Iplus,Iminus and delta localizations (hard)
  • Proposition 4.4: specific universal admissible ring R0 and parameter evaluation maps (hard)
  • Lemma 6.1: geometric affine (2,0)-tangle quotient, Y action and cup (hard)
  • Proposition 6.2: geometric cyclotomic KT0, empty diagram inclusion and weak admissibility (hard)
  • Lemma 7.3: labelled Brauer concatenation algebra over Rc and closure trace (hard)
  • Theorem 8.1: generic admissible coefficient ring, explicit lifted word family, closure trace and canonical geometric map (hard)
  • Corollary 8.2: admissible general-ring basis family and canonical BMW-to-geometric-KT map (hard)
  • Unnumbered: general admissibility equivalences: general admissibility polynomials and the rank-k B2 module of (47) (hard)
  • Unnumbered: admissibility implies weak admissibility: integer loop extension by (57) and nonsplit admissibility predicates (hard)
  • Unnumbered: canonical diagram map and specialization: canonical geometric psi, tangle coefficient specialization and generator-preserving BMW base change (hard)
  • Unnumbered: closure traces and specialization: unnormalized geometric closure traces and their specialization maps (hard)
  • Unnumbered: Brauer specialization: canonical Brauer specialization xi, Rc, coefficient quotient maps and both traces (hard)
  • Unnumbered: injective strand inclusions: canonical generator-preserving strand homomorphisms of nonsplit admissible BMW algebras (hard)

Selected references

  • On the freeness of the cyclotomic BMW algebras: admissibility and an isomorphism with the cyclotomic Kauffman tangle algebras, arXiv:0911.5284v1, https://arxiv.org/abs/0911.5284v1
13 thms2 active usersReviewed
🏆Completed
Quantum Information·Captain: Goku

Efficient Quantum Circuits for Schur and Clebsch-Gordan TransformsResearch Paper

Motivation

The Schur basis on n d-dimensional quantum systems is a generalization of the total angular momentum basis that is useful for exploiting symmetry under permutations or collective unitary rotations. We present efficient (size poly(n,d,log(1/ε)) for accuracy ε) quantum circuits for the Schur transform, which is the change of basis between the computational and the Schur bases. These circuits are based on efficient circuits for the Clebsch-Gordan transformation. We also present an efficient circuit for a limited version of the Schur transform in which one needs only to project onto different Schur subspaces. This second circuit is based on a generalization of phase estimation to any nonabelian finite group for which there exists a fast quantum Fourier transform.

This mission is the statement-level formalization of Efficient Quantum Circuits for Schur and Clebsch-Gordan Transforms (arXiv:quant-ph/0407082v4). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

4 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is The qubit CG step is three logical register operations (Eq.(6), Fig.1; continued on PDF p.3, PDF p. 2). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

6 results of the paper are not stated yet, because the library lacks an interface they need:

  • Abstract; Eq.(5) PDF p.2; final construction paragraph PDF p.3: A fixed source-compatible full Schur basis family and named clean qubit encodings, with an actual elementary-circuit approximation contract. (hard)
  • Fig.2; general-d cascade paragraph PDF p.3: An independently characterized general-d Schur target, compatible one-box CG intertwiners, and exact sequential path-register interpreter. (hard)
  • Abstract and general-d construction PDF p.3: A fixed finite source-compatible all-label one-qudit CG target and clean qubit implementation interface. (hard)
  • The complexity of this circuit is thus O(n · poly log(1/epsilon)): A declared per-step versus total epsilon and a charged spin-register arithmetic cost for the printed sharp bound. (source-ambiguity)
  • Eqs.(7),(10),(11): A true literal displayed output identity compatible with the printed Fourier convention and row/column labels. (source-ambiguity)
  • Furthermore, for large qudit dimension d, the new circuit is exponentially faster ...: A lower growth bound or explicit compared full-circuit cost in a specified simultaneous n,d regime. (source-ambiguity)

Selected references

  • Efficient Quantum Circuits for Schur and Clebsch-Gordan Transforms, arXiv:quant-ph/0407082v4, https://arxiv.org/abs/quant-ph/0407082v4
9 thms2 active usersReviewed
🏆Completed
Graph TheoryLinear algebraMachine Learning·Captain: mikedeng1

Geometric Deep Learning V: A Degree-r Polynomial Filter Σ αₖΔᵏX of a Graph Laplacian Is Localised in r-Hop NeighbourhoodsTextbook

Motivation

Graph neural networks and geometric learning on meshes rely on operators that combine the features of a node with those of its neighbours. The graph Laplacian is the oldest such operator: it is the discrete analogue of the Laplace–Beltrami operator of a surface, and its eigenvectors play the role of a Fourier basis on a graph. Early spectral graph networks (Bruna et al., 2013) learned filters directly in that eigenbasis. Such filters are expensive, since they need an eigendecomposition, and they do not transfer between graphs. Defferrard, Bresson and Vandergheynst (2016) replaced them with polynomial filters p^(Δ)X=∑k=0rαkΔkX\hat p(\Delta)X=\sum_{k=0}^r\alpha_k\Delta^kXp^​(Δ)X=∑k=0r​αk​ΔkX. These are computed with rrr sparse matrix products, and their output at a node depends only on a bounded neighbourhood of that node.

This mission formalizes Section 4.6 of the book Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges by Bronstein, Bruna, Cohen and Veličković (arXiv:2104.13478v2). The section introduces the weighted Laplacian (24) and the spectral and polynomial filters built on it, and states that a polynomial filter of degree rrr is localised in the rrr-hop neighbourhood. The section closes with the view of meshes as operators QQQ, which leads to remeshing invariance and to the result of Wang et al. (2019a) that remeshing-invariant functions depend only on the spectrum. The book numbers no theorems, lemmas or definitions, so every item of this mission is cited by section, equation number and printed page.

Setting

There are nnn nodes {1,…,n}\{1,\dots,n\}{1,…,n}. A weight matrix W=(wuv)∈Rn×nW=(w_{uv})\in\mathbb R^{n\times n}W=(wuv​)∈Rn×n assigns a weight to each ordered pair of nodes. The neighbourhood of uuu is Nu={v:wuv≠0}\mathcal N_u=\{v: w_{uv}\ne0\}Nu​={v:wuv​=0}. Node features form a matrix X∈Rn×dX\in\mathbb R^{n\times d}X∈Rn×d whose row xux_uxu​ is the ddd-dimensional feature vector of node uuu.

The degree of uuu is du=∑vwuvd_u=\sum_v w_{uv}du​=∑v​wuv​, and the degree matrix is D=diag⁡(d1,…,dn)D=\operatorname{diag}(d_1,\dots,d_n)D=diag(d1​,…,dn​). The Laplacian is

Δ=D−W,(ΔX)u=∑v∈Nuwuv(xu−xv).(24)\Delta=D-W,\qquad (\Delta X)_u=\sum_{v\in\mathcal N_u}w_{uv}(x_u-x_v).\tag{24}Δ=D−W,(ΔX)u​=v∈Nu​∑​wuv​(xu​−xv​).(24)

The graph is undirected when W=W⊤W=W^\topW=W⊤; then Δ\DeltaΔ is symmetric and has an orthonormal eigenbasis Φ=(φ1,…,φn)\Phi=(\varphi_1,\dots,\varphi_n)Φ=(φ1​,…,φn​) with Δ=ΦΛΦ⊤\Delta=\Phi\Lambda\Phi^\topΔ=ΦΛΦ⊤ and Λ=diag⁡(λ1,…,λn)\Lambda=\operatorname{diag}(\lambda_1,\dots,\lambda_n)Λ=diag(λ1​,…,λn​). The Fourier coefficients of XXX are X^=Φ⊤X\hat X=\Phi^\top XX^=Φ⊤X.

Given a degree rrr and real coefficients α0,…,αr\alpha_0,\dots,\alpha_rα0​,…,αr​, the polynomial filter is

p^(Δ)X=∑k=0rαkΔkX,p^(λ)=∑k=0rαkλk.\hat p(\Delta)X=\sum_{k=0}^r\alpha_k\Delta^kX ,\qquad \hat p(\lambda)=\sum_{k=0}^r\alpha_k\lambda^k .p^​(Δ)X=k=0∑r​αk​ΔkX,p^​(λ)=k=0∑r​αk​λk.

Hops are measured in a simple graph GGG on the nodes that carries the weights: wuv≠0w_{uv}\ne0wuv​=0 with u≠vu\ne vu=v implies that uuu and vvv are adjacent. A node vvv is within rrr hops of uuu if some walk in GGG from uuu to vvv has length at most rrr.

A permutation σ\sigmaσ of the nodes acts by its permutation matrix PPP, with (PX)u=xσ−1(u)(PX)_u=x_{\sigma^{-1}(u)}(PX)u​=xσ−1(u)​ and W↦PWP⊤W\mapsto PWP^\topW↦PWP⊤. A function fff of n×nn\times nn×n matrices QQQ is remeshing invariant if f(CQC⊤)=f(Q)f(CQC^\top)=f(Q)f(CQC⊤)=f(Q) for every orthogonal C∈O(n)C\in O(n)C∈O(n). A matrix-valued FFF is remeshing equivariant if CF(Q)=F(CQC⊤)CF(Q)=F(CQC^\top)CF(Q)=F(CQC⊤).

Formalization targets

Goal: locality of polynomial filters (p. 65)

If XXX and X′X'X′ agree at every node within rrr hops of uuu, then

(∑k=0rαkΔkX)u=(∑k=0rαkΔkX′)u\Big(\sum_{k=0}^r\alpha_k\Delta^kX\Big)_u=\Big(\sum_{k=0}^r\alpha_k\Delta^kX'\Big)_u(k=0∑r​αk​ΔkX)u​=(k=0∑r​αk​ΔkX′)u​

for every choice of α0,…,αr\alpha_0,\dots,\alpha_rα0​,…,αr​. This is the book's sentence "since the Laplacian is local, a polynomial filter of degree rrr is localised in rrr-hop neighbourhood". The statement fixes no coefficients and no graph family.

Milestones

  1. (24), p. 62. (ΔX)u=∑v∈Nuwuv(xu−xv)=duxu−∑v∈Nuwuvxv(\Delta X)_u=\sum_{v\in\mathcal N_u}w_{uv}(x_u-x_v)=d_ux_u-\sum_{v\in\mathcal N_u}w_{uv}x_v(ΔX)u​=∑v∈Nu​​wuv​(xu​−xv​)=du​xu​−∑v∈Nu​​wuv​xv​. The matrix D−WD-WD−W is the local difference operator.
  2. p. 62. F(X)=ΔXF(X)=\Delta XF(X)=ΔX is permutation equivariant: Δ(PWP⊤)(PX)=P Δ(W)X\Delta(PWP^\top)(PX)=P\,\Delta(W)XΔ(PWP⊤)(PX)=PΔ(W)X.
  3. Side-note, p. 64. If W=W⊤W=W^\topW=W⊤, then Δ\DeltaΔ is symmetric and Δ=ΦΛΦ⊤\Delta=\Phi\Lambda\Phi^\topΔ=ΦΛΦ⊤ with Φ\PhiΦ orthogonal.
  4. p. 64. If Δ=ΦΛΦ⊤\Delta=\Phi\Lambda\Phi^\topΔ=ΦΛΦ⊤, then ∑kαkΔkX=Φdiag⁡(p^(λ1),…,p^(λn))X^\sum_k\alpha_k\Delta^kX=\Phi\operatorname{diag}(\hat p(\lambda_1),\dots,\hat p(\lambda_n))\hat X∑k​αk​ΔkX=Φdiag(p^​(λ1​),…,p^​(λn​))X^.

Companions (p. 67)

  • The result of Wang et al. (2019a): if Q=VΛV⊤Q=V\Lambda V^\topQ=VΛV⊤ with VVV orthogonal, then f(Q)=f(Λ)f(Q)=f(\Lambda)f(Q)=f(Λ) for a remeshing-invariant fff, and F(Q)=VF(Λ)F(Q)=VF(\Lambda)F(Q)=VF(Λ) for a remeshing-equivariant FFF.
  • A remeshing-invariant fff takes equal values on symmetric matrices with the same characteristic polynomial.
  • Permutation matrices satisfy P⊤P=IP^\top P=IP⊤P=I, so remeshing invariance implies permutation invariance and equivariance.

Significance

The result. Locality is what separates polynomial filters from general spectral filters. A spectral filter Φp^(Λ)Φ⊤\Phi\hat p(\Lambda)\Phi^\topΦp^​(Λ)Φ⊤ with an arbitrary transfer function p^\hat pp^​ is a dense matrix: every output depends on every input. A degree-rrr polynomial filter has support inside the rrr-hop neighbourhood, so it costs rrr sparse matrix products and has a receptive field controlled by rrr. Milestone 4 shows that the same object is also a spectral filter, with transfer function p^\hat pp^​. A polynomial filter is therefore both a spectral filter and a message-passing operation. The book's discussion of rational filters on the same page, which have exponential decay but no local support, uses this contrast. The remeshing companions give the reason spectral constructions are used across different meshes: a remeshing-invariant function of the operator sees only the spectrum.

The formalization. The mathematics is classical, and the mission is about formalizing it. Mathlib has the unweighted combinatorial Laplacian SimpleGraph.lapMatrix and the spectral theorem for Hermitian matrices. The platform has a proved theorem counting walks with powers of an unweighted adjacency matrix. Neither gives the support of powers of a weighted Laplacian, whose nonzero diagonal is not covered by walk counts of a fixed length. None of the statements here is formalized on the platform. The mission produces a reusable support lemma for matrix polynomials of a graph-supported matrix, and a link between spectral and polynomial filters in the matrix language used by graph neural networks.

Difficulty

A first attempt identifies (Δk)uv(\Delta^k)_{uv}(Δk)uv​ with a count of walks of length exactly kkk, as for the adjacency matrix. That identification fails here. Δ\DeltaΔ has the diagonal entries dud_udu​, so (Δk)uv(\Delta^k)_{uv}(Δk)uv​ sums over walks that may pause at a node, and it can be nonzero for vvv at any distance up to kkk. The claim is therefore "within at most kkk hops", and the induction has to track walks of length at most kkk through a matrix with nonzero diagonal. Two encodings make the claim easy and wrong. Mathlib's SimpleGraph.dist is 000 for unreachable pairs, so "dist⁡(u,v)≤r\operatorname{dist}(u,v)\le rdist(u,v)≤r" would place every unreachable node inside the neighbourhood. A filter defined through the eigendecomposition is not visibly local, so the locality statement has to be about ∑kαkΔk\sum_k\alpha_k\Delta^k∑k​αk​Δk itself. For the companions, the difficulty is the spectral theorem and the fact that two symmetric matrices with the same characteristic polynomial are orthogonally similar, which requires matching eigenvalue lists up to a permutation.

Formalization scope

Matrices are Matrix (Fin n) (Fin n) ℝ, and features are Matrix (Fin n) (Fin d) ℝ, with rows as nodes. The Laplacian is the published definition SpectralSparsify.Sampling.lapMat (degree matrix minus weight matrix), referenced rather than redefined and used under the local name lap. It imposes no condition on WWW. A diagonal weight wuuw_{uu}wuu​ cancels in D−WD-WD−W. Symmetry W=W⊤W=W^\topW=W⊤ is assumed only where the book needs it: the side-note on p. 64. The polynomial filter is the explicit sum ∑k=0rαkΔk\sum_{k=0}^r\alpha_k\Delta^k∑k=0r​αk​Δk with coefficients indexed by {0,…,r}\{0,\dots,r\}{0,…,r}. "Within rrr hops" is the existence of a walk of length at most rrr in a simple graph GGG that contains the support of WWW. The goal is stated for every such GGG and for non-symmetric WWW. Both are generalisations of the book's undirected setting, where GGG is the graph of WWW. Permutation matrices act by moving row σ−1(u)\sigma^{-1}(u)σ−1(u) to row uuu. Remeshing invariance quantifies over all of Mathlib's orthogonalGroup. "The same spectrum" is equality of characteristic polynomials of symmetric matrices.

A trivializing formalization is ruled out: the filter is not defined through an eigendecomposition, "localised" is not defined as "is a polynomial in Δ\DeltaΔ", and the hop condition is not stated through the junk-valued SimpleGraph.dist.

A complete development needs the support of products of graph-supported matrices, the spectral theorem in orthogonal form (Mathlib's Matrix.IsHermitian.eigenvectorUnitary), and orthogonal similarity of symmetric matrices with equal characteristic polynomials. The support lemma is reusable for any message-passing operator that is a polynomial in a local matrix. Contributions of these lemmas, and alternative proofs (for example through Polynomial.aeval), are welcome.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen, P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint, 2021, §4.6, pp. 62–67. https://arxiv.org/abs/2104.13478
  • M. Defferrard, X. Bresson, P. Vandergheynst, Convolutional Neural Networks on Graphs with Fast Localized Spectral Filtering, NeurIPS, 2016. https://arxiv.org/abs/1606.09375
  • J. Bruna, W. Zaremba, A. Szlam, Y. LeCun, Spectral Networks and Locally Connected Networks on Graphs, ICLR, 2014. https://arxiv.org/abs/1312.6203
  • R. Levie, F. Monti, X. Bresson, M. M. Bronstein, CayleyNets: Graph Convolutional Neural Networks with Complex Rational Spectral Filters, IEEE Trans. Signal Processing, 2018. https://arxiv.org/abs/1705.07664
  • Y. Wang, V. Kim, M. Bronstein, J. Solomon, Learning Geometric Operators on Meshes, ICLR Workshops, 2019 (the book's "Wang et al. 2019a"; no arXiv version is listed in the book's bibliography, PDF p. 157 of https://arxiv.org/abs/2104.13478v2).
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Graph TheoryGroup TheoryMachine Learning·Captain: mikedeng1

Geometric Deep Learning VII: The E(3)-Equivariant Message-Passing Layer Leaves Node Features Invariant and Moves Coordinates with Every Rigid MotionTextbook

Motivation

Many graphs that graph neural networks (GNNs) are applied to are embedded in space. In a molecular graph the nodes are atoms, and each atom carries both chemical information (its type) and its three-dimensional position. A prediction about the molecule (an energy, a binding affinity) must not depend on where the molecule sits or how it is oriented, and a predicted geometry must move with the molecule. Bronstein, Bruna, Cohen and Veličković's Geometric Deep Learning (arXiv:2104.13478v2, 2021) treats this in §5.5, Equivariant Message Passing Networks: a layer on such graphs should be equivariant to the Euclidean group E(3) of rigid motions "in addition to the standard permutation equivariance discussed before" (p. 83). The book presents the layer of Satorras, Hoogeboom and Welling, E(n) Equivariant Graph Neural Networks (ICML 2021, arXiv:2102.09844), and asserts that it has this property.

The layer is built from the most general of the three "flavours" of GNN layer that §5.3 uses to organise the literature: convolutional, attentional and message passing. This mission therefore also formalizes the two claims of §5.3 that the E(3) layer relies on: message passing is permutation equivariant, and it contains the other two flavours.

The book numbers no theorem, lemma or definition. Every item of this mission is cited by section, equation number (where there is one) and printed page.

Setting

A graph on the nodes V={1,…,n}V = \{1,\dots,n\}V={1,…,n} is given by an adjacency matrix A∈Rn×n\mathbf A\in\mathbb R^{n\times n}A∈Rn×n, with an edge (u,v)(u,v)(u,v) whenever auv≠0a_{uv}\neq0auv​=0. The neighbourhood of uuu is Nu={v:(u,v)∈E or (v,u)∈E}\mathcal N_u = \{v : (u,v)\in E \text{ or } (v,u)\in E\}Nu​={v:(u,v)∈E or (v,u)∈E} (eq. (11), p. 34). Each node carries a feature xu\mathbf x_uxu​; collected as rows they form the feature matrix X\mathbf XX. A permutation σ\sigmaσ of the nodes, with permutation matrix P\mathbf PP, acts by X↦PX\mathbf X\mapsto\mathbf{PX}X↦PX and A↦PAP⊤\mathbf A\mapsto\mathbf{PAP}^\topA↦PAP⊤. A layer FFF is permutation equivariant if F(PX,PAP⊤)=PF(X,A)F(\mathbf{PX},\mathbf{PAP}^\top) = \mathbf P F(\mathbf X,\mathbf A)F(PX,PAP⊤)=PF(X,A) (eq. (10), p. 33).

A permutation-invariant aggregator ⨁\bigoplus⨁ is a function of the multiset of incoming values ("sum, mean, or maximum", p. 78). The three flavours of §5.3 (p. 79), with an update function ϕ\phiϕ, are

(33)  hu=ϕ(xu,⨁v∈Nucuvψ(xv)),(34)  hu=ϕ(xu,⨁v∈Nua(xu,xv)ψ(xv)),(35)  hu=ϕ(xu,⨁v∈Nuψ(xu,xv)):\text{(33)}\ \ \mathbf h_u = \phi\Big(\mathbf x_u, \bigoplus_{v\in\mathcal N_u} c_{uv}\psi(\mathbf x_v)\Big),\qquad \text{(34)}\ \ \mathbf h_u = \phi\Big(\mathbf x_u, \bigoplus_{v\in\mathcal N_u} a(\mathbf x_u,\mathbf x_v)\psi(\mathbf x_v)\Big),\qquad \text{(35)}\ \ \mathbf h_u = \phi\Big(\mathbf x_u, \bigoplus_{v\in\mathcal N_u} \psi(\mathbf x_u,\mathbf x_v)\Big):(33)  hu​=ϕ(xu​,v∈Nu​⨁​cuv​ψ(xv​)),(34)  hu​=ϕ(xu​,v∈Nu​⨁​a(xu​,xv​)ψ(xv​)),(35)  hu​=ϕ(xu​,v∈Nu​⨁​ψ(xu​,xv​)):

convolutional with fixed coefficients cuvc_{uv}cuv​, attentional with an attention mechanism aaa of the features, and message passing with a message function ψ\psiψ of receiver and sender.

In §5.5 each node carries features fu∈Rd\mathbf f_u\in\mathbb R^dfu​∈Rd and spatial coordinates xu∈R3\mathbf x_u\in\mathbb R^3xu​∈R3. An element g∈E(3)g\in\mathrm E(3)g∈E(3) acts on coordinates by ρ(g)x=Rx+b\rho(g)\mathbf x = \mathbf R\mathbf x + \mathbf bρ(g)x=Rx+b, "where R\mathbf RR is an orthogonal matrix modeling rotations and reflections, and b\mathbf bb is a translation vector" (p. 83). The equivariant message-passing layer (p. 84) is

fu′=ϕ(fu,⨁v∈Nuψf(fu,fv,∥xu−xv∥2)),xu′=xu+∑v≠u(xu−xv) ψc(fu,fv,∥xu−xv∥2),\mathbf f'_u = \phi\Big(\mathbf f_u, \bigoplus_{v\in\mathcal N_u}\psi_{\mathrm f}(\mathbf f_u,\mathbf f_v,\|\mathbf x_u-\mathbf x_v\|^2)\Big),\qquad \mathbf x'_u = \mathbf x_u + \sum_{v\neq u}(\mathbf x_u-\mathbf x_v)\,\psi_{\mathrm c}(\mathbf f_u,\mathbf f_v,\|\mathbf x_u-\mathbf x_v\|^2),fu′​=ϕ(fu​,v∈Nu​⨁​ψf​(fu​,fv​,∥xu​−xv​∥2)),xu′​=xu​+v=u∑​(xu​−xv​)ψc​(fu​,fv​,∥xu​−xv​∥2),

with ψf\psi_{\mathrm f}ψf​ and ψc\psi_{\mathrm c}ψc​ "two distinct (learnable) functions", ψc\psi_{\mathrm c}ψc​ scalar-valued. The book's desired property (p. 83): if the spatial input is transformed by ggg, "the spatial component of the output transforms in the same way (as xu′↦Rxu′+b\mathbf x'_u\mapsto\mathbf R\mathbf x'_u+\mathbf bxu′​↦Rxu′​+b), whereas fu′\mathbf f'_ufu′​ remains invariant."

Formalization targets

Goal: E(3) equivariance of the layer (§5.5, pp. 83–84)

For every orthogonal R∈O(3)\mathbf R\in O(3)R∈O(3) and b∈R3\mathbf b\in\mathbb R^3b∈R3, applying the layer to (f,Rx+b)(\mathbf f, \mathbf R\mathbf x+\mathbf b)(f,Rx+b) gives (f′′,x′′)(\mathbf f'', \mathbf x'')(f′′,x′′) with

fu′′=fu′,xu′′=Rxu′+bfor every node u.\mathbf f''_u = \mathbf f'_u,\qquad \mathbf x''_u = \mathbf R\mathbf x'_u + \mathbf b\qquad\text{for every node } u.fu′′​=fu′​,xu′′​=Rxu′​+bfor every node u.

The statement holds for arbitrary ϕ\phiϕ, ψf\psi_{\mathrm f}ψf​, ψc\psi_{\mathrm c}ψc​ and ⨁\bigoplus⨁; nothing about the learnable functions is fixed.

Milestones

  1. E(3) preserves distances (§5.5, p. 84): ∥(Rx+b)−(Ry+b)∥=∥x−y∥\|(\mathbf R\mathbf x+\mathbf b)-(\mathbf R\mathbf y+\mathbf b)\| = \|\mathbf x-\mathbf y\|∥(Rx+b)−(Ry+b)∥=∥x−y∥, the reason the book gives for the goal.
  2. Message passing is permutation equivariant (§5.3, pp. 78–79): (35) satisfies F(PX,PAP⊤)=PF(X,A)F(\mathbf{PX},\mathbf{PAP}^\top)=\mathbf PF(\mathbf X,\mathbf A)F(PX,PAP⊤)=PF(X,A).
  3. Convolution ⊆ attention ⊆ message passing (§5.3, pp. 79–80). The book continues on p. 80: "attentional GNNs are special cases of message-passing where the messages are only the sender nodes’ features: ψ(xu, xv) = cuvψ(xv) for convolutional GNNs and ψ(xu, xv) = a(xu, xv)ψ(xv) for attentional GNNs." Attention is message passing with messages a(xu,xv)ψ(xv)a(\mathbf x_u,\mathbf x_v)\psi(\mathbf x_v)a(xu​,xv​)ψ(xv​); when the features identify the nodes, convolution is attention with a look-up table a(xu,xv)=cuva(\mathbf x_u,\mathbf x_v)=c_{uv}a(xu​,xv​)=cuv​ and message passing with messages cuvψ(xv)c_{uv}\psi(\mathbf x_v)cuv​ψ(xv​).
  4. The layer is message passing (§5.5, p. 84): the feature update is (35) on A\mathbf AA with node state (fu,xu)(\mathbf f_u,\mathbf x_u)(fu​,xu​); the coordinate update is (35) on the complete graph without self-loops, with the sum as aggregator.

Significance

The equivariance of the layer is what lets a network built from it be applied to molecules and point clouds without data augmentation over rotations, reflections and translations: invariant outputs are unaffected by the placement of the input, and coordinate outputs move with it. Satorras et al. use the layer, stacked, for molecular property prediction, dynamical systems and graph autoencoders; the equivariance of the stack follows from that of each layer. The containment of the three flavours explains why the book can discuss GNN expressivity (Ch. 7, chunk IX of this series) for message passing alone.

The results are known and their proofs are short computations; none of them has a machine-checked proof on the platform. Formalizing them pins down what the claims mean exactly: that the reflections in O(3)O(3)O(3) are included, that the translation enters the coordinate update only through the leading xu\mathbf x_uxu​, and under which condition on the features the containment "convolution ⊆ attention" actually holds.

Difficulty

The mathematics is elementary; the difficulty is in stating the claims at the generality the book uses. The coordinate update is not a function of distances alone: it is linear in the difference vectors xu−xv\mathbf x_u-\mathbf x_vxu​−xv​, and equivariance rests on ψc\psi_{\mathrm c}ψc​ being scalar-valued and on the translation cancelling in every difference but surviving in the leading term. The containment "convolution ⊆ attention" fails as a literal identity when two nodes have equal features but different coefficients cuvc_{uv}cuv​, since an attention mechanism sees only features; the book's look-up table needs features that identify the nodes. The two halves of the layer aggregate over different index sets (Nu\mathcal N_uNu​ and all v≠uv\neq uv=u), so the layer is message passing on two different graphs.

Formalization scope

Nodes are Fin n. Node features are a family Fin n → α (for α=Rd\alpha=\mathbb R^dα=Rd this is the book's matrix X\mathbf XX, Matrix (Fin n) (Fin d) ℝ). The aggregator ⨁\bigoplus⨁ is an arbitrary function Multiset M → M' of the multiset of messages, so its permutation invariance holds by construction. A permutation acts by (PX)_u = X_{σ⁻¹(u)} and (PAPᵀ)_{uv} = A_{σ⁻¹(u)σ⁻¹(v)}. Coordinates live in EuclideanSpace ℝ (Fin 3); R\mathbf RR ranges over Matrix.orthogonalGroup (Fin 3) ℝ, the whole of O(3)O(3)O(3) including reflections, acting through Matrix.toEuclideanLin. The squared norm ∥xu−xv∥2\|\mathbf x_u-\mathbf x_v\|^2∥xu​−xv​∥2 is kept as printed. No standing assumption of the section restricts nnn or ddd; n=0n = 0n=0 is allowed.

The layer takes the coordinates themselves as input. A formalization that fed the layer only the distance matrix would make the feature half trivially invariant and drop the coordinate half; that encoding is ruled out.

One hypothesis is added relative to the page, in milestone 3 only: the features must be pairwise distinct (Function.Injective X) for convolution to be represented by attention or by message passing. Without it the claim is false, and a two-node counterexample is checked in Lean. The inclusion of attention in message passing needs no hypothesis.

The definitions of this mission (neighbourhoods, the permutation action, the three flavours) duplicate objects of chunk II of this series; drafts cannot import drafts, and the duplicates are to be merged after the series is published. Proofs of every item are welcome; the distance lemma, the orthogonal-matrix isometry and the multiset reindexing under a permutation are reusable beyond this mission.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen, P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint, 2021. https://arxiv.org/abs/2104.13478v2
  • V. G. Satorras, E. Hoogeboom, M. Welling, E(n) Equivariant Graph Neural Networks, ICML 2021. https://arxiv.org/abs/2102.09844
  • J. Gilmer, S. S. Schoenholz, P. F. Riley, O. Vinyals, G. E. Dahl, Neural Message Passing for Quantum Chemistry, ICML 2017. https://arxiv.org/abs/1704.01212
  • P. Veličković, G. Cucurull, A. Casanova, A. Romero, P. Liò, Y. Bengio, Graph Attention Networks, ICLR 2018. https://arxiv.org/abs/1710.10903
  • T. N. Kipf, M. Welling, Semi-Supervised Classification with Graph Convolutional Networks, ICLR 2017. https://arxiv.org/abs/1609.02907
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Mathematical Physics·Captain: Lucas

On the dimensionality of spacetime: the PDE trichotomy, the data hyperplanes, the Green profile, the orbit-stability dichotomy, and the selection of (3+1)(3 + 1)(3+1) dimensionsResearch Paper

On the dimensionality of spacetime: the PDE trichotomy, the data hyperplanes, the Green profile, the orbit-stability dichotomy, and the selection of (3 + 1) dimensions

1. Motivation

Max Tegmark's letter "On the dimensionality of spacetime" (Classical and Quantum Gravity 14 (1997) L69-L75) is the standard reference for the anthropic selection argument on the dimensionality of spacetime. Many superstring theories and inflationary models predict not a single classical spacetime but an ensemble of effective low-energy worlds with different numbers n of space and m of time dimensions, together with a probability distribution over the pairs (n, m). Tegmark argues that this failure to predict (n, m) = (3, 1) uniquely is a strength rather than a weakness: the selection effect arising from the fact that only some worlds contain self-aware observers collapses the distribution, so that such an ensemble theory may predict that we should find ourselves inhabiting a (3 + 1)-dimensional spacetime with 100% certainty, the Bayesian prior probabilities being completely irrelevant.

The letter's argument has three prongs, and the mission formalizes the mathematical content of each. More or less than one time dimension destroys predictability: the partial differential equations of nature have the hyperbolicity property that makes initial-value problems well posed only when m = 1; with no time dimension the equations are elliptic and an observer could not make any inferences at all about other parts of space from local data; with two or more time dimensions no hypersurface carries well-posed data. More than three space dimensions destroys stability: the Green's function of the Poisson equation scales as the (2 - n)-th power of the radius, the two-body problem has no stable orbit solutions for n > 3, and, by the quantum counterpart the letter cites (Tangherlini), no traditional atoms exist. Fewer than three space dimensions destroys complexity: the letter conjectures that such worlds are too simple and barren to contain observers, citing the absence of gravitational force in general relativity with n < 3 and the topological problems of two-dimensional organisms.

The goal statement of the mission is the Bayesian capstone: in a world ensemble whose observer worlds satisfy the three prongs, the probability of being an observer in a (3, 1)-dimensional world equals the probability of being an observer, so that conditional on observerhood the dimensionality is (3, 1) with probability one. The milestones are the classification trichotomy of the field equations, the space-time symmetry of the classification, the hyperplane obstruction behind the letter's Asgeirsson discussion, the spacelike slice of the single-time world, the predictability equivalence, the harmonicity of the Green profile, and the orbit-stability dichotomy.

The source document is the uploaded letter (tegmark1997.pdf in the mission materials).

2. The formalization fragment and conventions

The formalization is a three-layer development in the namespace Tegmark. The signature layer (Tegmark_sig) fixes the coordinate model: a world with n space and m time dimensions is the coordinate space over the disjoint union of the n space directions and the m time directions, carrying the quadratic form teg that counts space coordinates positively and time coordinates negatively, so that a single minus sign distinguishes space from time. The layer defines the spacelike and timelike classification of vectors and submodules, the elliptic, hyperbolic, and ultrahyperbolic classes of the field equations, the hyperplanes on which initial data can be posed, and the predictability requirement. The physics layer (Tegmark_phys) carries the Newtonian potential of a point mass in n dimensions — the Green's-function scaling of the Poisson equation — the effective potential of the two-body problem with its circular-orbit and stability criteria, and the radially reduced Laplace equation with the Green profile. The ensemble layer (Tegmark_ensemble) carries the probability space of worlds with the two dimension counts and the measurable observer event.

The following choices are disclosed explicitly.

  1. Compile verification by CI substitution. The authoring environment has no local Lean toolchain, so the compile check demanded by the mission is performed by the continuous integration of the repository (Lean 4.33 with Mathlib): all Lean code below was compiled there before this proposal was submitted, and the code attached to the items is byte-identical to the compiled modules.

  2. The theorem drafts carry sorry. The eight theorem statements are submitted as drafts for human review; each proof body is a single sorry marking the work the mission proposes to complete. The compilation therefore succeeds with exactly one "declaration uses 'sorry'" warning per theorem file.

  3. The coordinate model. A world with (n, m) dimensions is the flat coordinate space over the disjoint union of the n space directions and the m time dimensions, with the signature form. This is the linear-algebra skeleton of the letter's discussion: the classification of the field equations by the eigenvalue signs of the principal symbol is a pointwise, linear matter, and the data-surface and Asgeirsson arguments take place on the hypersurfaces of the tangent space. The mission formalizes the letter's argument in this flat model, which carries it exactly; curved manifolds are not formalized (disclosure 13).

  4. The covariant case of the letter's equation (1). The letter classifies a general second-order linear partial differential equation by the signs of the eigenvalues of the coefficient matrix A of its displayed equation (1), with A, b, and c given functions of the coordinates. The mission formalizes the covariant case, the case the letter's dimensionality argument is about: for the wave equation and the Klein-Gordon equation the principal symbol has the same eigenvalue signs as the metric, so the class of the field equations is a function pdeClass of the pair (n, m) alone. The trichotomy milestone states the three equivalences this yields. Variable-coefficient equations, lower-order terms, and the nonlinear systems the letter mentions are out of scope; the letter's remark there (that no nonlinear terms can make a locally ill-posed problem well posed) is commentary on the classification, not a formalized claim.

  5. Well-posedness represented by the classification. The letter's predictability requirement is that the equations be hyperbolic, so that initial-value problems are well posed, and that the data can be posed on a spacelike hypersurface. The mission does not formalize the PDE theory behind this — Hadamard's well-posedness, the energy estimates, or Asgeirsson's theorem — but takes the classification as the formal content: the predicate Predictable is the conjunction of hyperbolicity of the class and the existence of a spacelike hyperplane. The milestone predictable_m1 then shows that the requirement holds exactly in the single-time worlds with at least one space dimension, which is the letter's time-dimension argument.

  6. Hyperplanes as data surfaces. A hypersurface on which initial data is posed is modeled as a hyperplane: the kernel of a nonzero linear functional; spacelike and timelike hyperplanes are the positive- and negative-definite kernels. The letter's statement that there are no space-like and no time-like hypersurfaces in the ultrahyperbolic case is formalized as the hyperplane obstruction: with at least two time dimensions no hyperplane is spacelike, and with at least two space dimensions no hyperplane is timelike. The deeper Asgeirsson phenomenon of the letter's figure 3 — data in an effectively one-dimensional region determining the solution in a higher-dimensional region, the free-lunch symptom of ill-posedness — is out of scope; the obstruction is the part of the discussion that is linear algebra, and it is what the predictability prong needs.

  7. The Green profile and the Newtonian potential. The potential of a point particle in n space dimensions is the Green's function of the Poisson equation, which scales as the (2 - n)-th power of the radius for n > 2 (Ehrenfest 1917, as the letter cites); the inverse-square law of electrostatics and gravity is the three-dimensional case, an inverse-cube law the four-dimensional one. The physics layer carries the Green profile and the radially reduced Laplace operator; the milestone green_harmonic verifies that the profile is harmonic away from the origin, the defining property of the fundamental solution. The Newtonian potential of the two-body problem is the coupling times the profile, up to sign. Real powers, real division, and deriv are noncomputable in the pinned Mathlib; the definitions of the physics layer that use them are marked noncomputable accordingly.

  8. Classical stability and the quantum counterpart. The letter argues the n > 3 instability with both the classical two-body problem (no stable orbits; the figure-2 swarm either escaping to infinity or spiralling into a cataclysmic collision) and the quantum hydrogen atom (no bound states, Tangherlini 1963). The mission formalizes the classical dichotomy in the effective-potential form: for n at least 3, stable circular Newtonian orbits exist exactly when n is 3. A circular orbit is a positive critical point of the effective potential (the centrifugal barrier plus the Newtonian potential); a stable one has positive curvature there, the linear stability of the orbit. The quantum atom, and the letter's remark that the general-relativistic situation is analogous, are out of scope, as disclosed in the exclusions.

  9. The complexity prong carried as a bound. The letter's third prong — that worlds with fewer than three space dimensions are too simple and barren to contain observers — is supported by citations the mission does not formalize (the absence of gravitational force in general relativity with n < 3; the crossing of nerves argument). The ensemble layer carries the prong as the abstract hypothesis on the observer worlds: at least three space dimensions, the complexity requirement, on a par with the stability requirement of at most three. The goal theorem quantifies over the ensembles satisfying the letter's three premises; it does not derive them, and the letter itself is explicit that it has "not attempted to rigorously demonstrate that observers are impossible for other dimensionalities".

  10. The ensemble layer and the capstone. A world ensemble is a measurable space of worlds with a probability measure, the two effective dimension counts of each world, and the measurable event of the worlds containing observers; nothing further is assumed. The goal theorem: if the observer worlds have positive measure and satisfy the predictability, stability, and complexity requirements, then the measure of the observer worlds inside the (3, 1) region equals the measure of all observer worlds. The positive-measure hypothesis is carried so that the equality reads as the letter's conditional statement ("with 100% certainty"); the measure equality itself is the division-free form of that conditional.

  11. Effective dimensionalities. The letter's n and m are the numbers of non-compactified space and time dimensions, or more generally the effective dimensionalities relevant to the low-energy physics; the mission's dimension counts are these effective numbers, as the letter's first footnote fixes.

  12. Definition names and module stems. The three definition bundles are published under names equal to their module stems (Tegmark_sig, Tegmark_phys, Tegmark_ensemble), so that the platform imports Definitions.Def_Tegmark_* in the theorem preambles resolve, in dependency order sig, then phys, then ensemble.

  13. Exclusions. Out of scope: the general variable-coefficient second-order PDE of the letter's equation (1) with arbitrary coefficient matrix; Hadamard well-posedness and Asgeirsson's theorem; curved manifolds and the general-relativistic no-gravity claim for n < 3 (Deser, Jackiw and 't Hooft, as the letter cites); the quantum hydrogen atom of Tangherlini and the letter's general-relativistic analogue; the particle-decay kinematics with m > 1 (Dorling) and the tachyon physics (Feinberg) beyond the classification symmetry; the superstring compactification and inflationary mechanisms behind the letter's ensembles; the topological nerve-crossing argument; and the null-hypersurface caveat of the letter's footnote (data posed on a light-cone hypersurface).

3. Formalization targets

The mission has eleven items: three reference definitions and eight theorem drafts, in the following order.

Reference definitions (the formalization fragment):

  • Tegmark_sig: the signature layer. The point space of an (n, m) world, the quadratic form with its spacelike and timelike classifications of vectors and submodules, the three PDE classes with the classifier read off the pair (n, m), the spacelike and timelike hyperplanes (the kernels of nonzero linear functionals on which the form is definite), and the predictability requirement: hyperbolic field equations together with a spacelike hyperplane.
  • Tegmark_phys: the physics layer. The Newtonian potential of a point mass in n dimensions, the effective two-body potential with its circular-orbit and stability criteria, the existence predicate for stable circular orbits, the radially reduced Laplace operator, and the radial Green profile.
  • Tegmark_ensemble: the ensemble layer. The probability space of worlds with a probability measure, the two effective dimension counts, and the measurable observer event.

Theorem drafts (milestones in attack order, then the goal):

  1. Tegmark.pde_trichotomy: the class of the field equations of an (n, m) world is elliptic exactly when there are no space or no time dimensions, hyperbolic exactly when there is at least one dimension of each kind and exactly one of one kind, and ultrahyperbolic exactly when there are at least two of each (pages L72-L73).
  2. Tegmark.tachyon_symmetry: the class is symmetric under exchanging the numbers of space and time dimensions (page L74).
  3. Tegmark.no_spacelike_hyperplane: with at least two time dimensions no hyperplane of the point space is spacelike, and with at least two space dimensions no hyperplane is timelike (page L74).
  4. Tegmark.spacelike_slice: every world with exactly one time dimension has a spacelike hyperplane, the spatial slice (pages L73-L74).
  5. Tegmark.predictable_m1: for a world with at least one space dimension, the predictability requirement holds exactly when the number of time dimensions is one (pages L72-L74).
  6. Tegmark.green_harmonic: for n at least 3, the radial Green profile satisfies the radially reduced Laplace equation at every positive radius (page L70).
  7. Tegmark.orbit_stability_31: for n at least 3, the Newtonian two-body problem admits stable circular orbits exactly when n is 3 (pages L70-L71).
  8. Tegmark.selection_31 (the goal): in a world ensemble whose observer worlds have positive measure and satisfy the predictability, stability, and complexity requirements, the measure of the observer worlds in the (3, 1) region equals the measure of all observer worlds (pages L69-L70).

Milestones 1 to 7 correspond to the theorem drafts 1 to 7; the goal is draft 8.

4. Significance

The letter is the canonical modern statement of the argument that the dimensionality of spacetime is an anthropic prediction, and the standard citation for its three mathematical prongs: Ehrenfest's 1917 observation on the instability of worlds with more than three space dimensions, the Green's-function scaling behind the dimension-dependence of the force laws, and the hyperbolicity classification behind the predictability of worlds with exactly one time dimension. These prongs rest on classical results — Ehrenfest 1917, Tangherlini 1963, Asgeirsson 1936, the Courant-Hilbert classification — which exist in the physics and PDE literature but have not been formalized together in a proof assistant. The mission packages them as one Lean development with a shared coordinate model, and its capstone is a precise, checkable statement of the letter's Bayesian conclusion: the selection argument is exactly the measure-theoretic fact that a positive-measure event contained in a region carries the region's conditional probability. A formal account also disciplines the argument's edges: the mission's theorems hold exactly where the letter's prose is exact, and the letter's conjectural steps (the complexity prong, the barrenness of n < 3) enter the capstone as explicit hypotheses rather than as unexamined facts.

5. Difficulty

The trichotomy and symmetry milestones are definitional: the unfolding of the classifier and its symmetry, verifying that the mission's encoding matches the letter's three signature examples. The hyperplane milestones are genuine linear algebra: the obstruction argument must, for every nonzero functional on a space whose time block has at least two dimensions, exhibit a nonzero vector of its kernel inside the time block — a case split on whether the functional vanishes on the block — and the slice milestone evaluates the form on the projection's kernel. The physics milestones are calculus with real powers: harmonicity differentiates the (2 - n)-th power twice and cancels against the (n - 1)/r correction, and the orbit dichotomy reduces the curvature at a circular orbit to the factor (n - 2)(4 - n), whose sign is the three-case analysis n = 3, n = 4, n at least 5. The capstone is measure-theoretic bookkeeping over the ensemble: the collation of the predictability equivalence (which forces one time dimension), the stability bound (at most three space dimensions), and the complexity bound (at least three), pinning every observer world into the (3, 1) region.

6. Scope

Included: the letter's pages L69-L75 at the statement level — the coordinate model of an (n, m) world and its signature form; the covariant PDE classification by the numbers of space and time dimensions; the hyperplane obstruction for multi-time worlds and the spacelike slice of single-time worlds; the predictability equivalence; the harmonicity of the Green profile in n at least 3 dimensions; the effective-potential orbit-stability dichotomy for n at least 3; and the Bayesian capstone over world ensembles.

Excluded, as disclosed in item 13 of section 2: the general second-order PDE of the letter's equation (1) with variable coefficients; the well-posedness theory (Hadamard, the energy estimates, Asgeirsson's theorem) behind the classification; curved spacetimes and the general-relativistic claims; the quantum atom and its general-relativistic analogue; the m > 1 decay kinematics and the tachyon physics beyond the classification symmetry; the compactification mechanisms of the superstring and inflationary ensembles; the topological nerve-crossing argument; and the null-hypersurface caveat.

7. References

  • Max Tegmark, "On the dimensionality of spacetime", Classical and Quantum Gravity 14 (1997) L69-L75. The source document is the uploaded letter (tegmark1997.pdf); also available as arXiv:gr-qc/9702052.
  • P. Ehrenfest, "In what way does it become manifest in the fundamental laws of physics that space has three dimensions?", Proc. Amsterdam Acad. 20 (1917) 200.
  • F. R. Tangherlini, "Schwarzschild field in n dimensions and the dimensionality of space-time", Nuovo Cimento 27 (1963) 636.
  • L. Asgeirsson, "On some methods of solving linear partial differential equations by means of definite integrals", Math. Ann. 113 (1936) 321.
  • R. Courant and D. Hilbert, Methods of Mathematical Physics, vol. II, Interscience, New York, 1962 (the letter's reference for the PDE classification and causality).
  • J. Dorling, "The dimensionality of time", Am. J. Phys. 38 (1970) 539 (the letter's reference for the decay kinematics with several time dimensions).
  • B. Carter, "Large number coincidences and the anthropic principle in cosmology", IAU Symposium 63 (1974); J. D. Barrow and F. J. Tipler, The Anthropic Cosmological Principle, Oxford University Press, 1986 (the letter's references for the weak anthropic principle).
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Quantum Information·Captain: Goku

Gelfand-type duality for commutative von Neumann algebrasResearch Paper

Motivation

We show that the following five categories are equivalent: (1) the opposite category of commutative von Neumann algebras; (2) compact strictly localizable enhanced measurable spaces; (3) measurable locales; (4) hyperstonean locales; (5) hyperstonean spaces. This result can be seen as a measure-theoretic counterpart of the Gelfand duality between commutative unital C*-algebras and compact Hausdorff topological spaces.

This mission is the statement-level formalization of Gelfand-type duality for commutative von Neumann algebras (arXiv:2005.05284v3). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

13 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Continuous and completely additive finite valuations (Lemma 2.21, PDF p. 10). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

51 results of the paper are not stated yet, because the library lacks an interface they need:

  • Theorem 1.1: Locale; Omega; Sp; OpenLocaleMap; COpen; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; Predual; CVNA; ProjAlg; ProjLoc; LocalicLInfinity; Step; ValuationPredual; LocalicIntegral; Chi; Mu; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML; Epsilon; LiftingSection; Eta (hard)
  • Theorem 1.2: Locale; Omega; Sp; OpenLocaleMap; COpen; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; NormalMeasure; Predual; CVNA; ProjAlg; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; EssentialMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML (hard)
  • Pretheorem 1.9: Locale; Omega; OpenLocaleMap; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; Predual; CVNA; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; FiberwiseMeasures (source-ambiguity)
  • Pretheorem 1.11: Locale; Omega; OpenLocaleMap; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; Predual; CVNA; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; HilbertBundles (source-ambiguity)
  • Proposition 2.27: Locale; Omega; Sp; SpatialLocale; CoherentSpace (hard)
  • Proposition 2.31: Locale; COpen; Ideal (hard)
  • Proposition 2.38: Locale; Omega; Sp; CoherentSpace (hard)
  • Proposition 2.41: Locale; COpen; Ideal (hard)
  • Lemma 2.44: Locale; OpenLocaleMap; CBAlg (hard)
  • Proposition 2.47: Locale; Omega; Sp; OpenLocaleMap; StoneanSpace (hard)
  • Proposition 2.48: Locale; OpenLocaleMap; COpen; Ideal; CBAlg (hard)
  • Lemma 2.58: Locale; Sublocale; OpenLocaleMap; COpen; CBAlg; DoubleNegation (hard)
  • Lemma 2.65: Locale; StoneanSpace; NormalMeasure; NormalIntegral (hard)
  • Lemma 2.67: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; NormalMeasure; BaireEnhanced (hard)
  • Lemma 2.68: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; BaireEnhanced (hard)
  • Lemma 2.69: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; NormalMeasure; BaireEnhanced (hard)
  • Lemma 2.71: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; NormalMeasure (hard)
  • Proposition 2.72: Locale; Omega; Sp; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean (hard)
  • Proposition 2.73: Locale; OpenLocaleMap; COpen; Ideal; CBAlg; LBAlg; MLoc; HStoneanLoc (hard)
  • Proposition 3.8: CBAlg; LBAlg; Predual; CVNA; ProjAlg (hard)
  • Proposition 3.9: CBAlg; LBAlg; Predual; CVNA; ProjAlg (hard)
  • Lemma 3.11: Locale; CBAlg; LBAlg; MLoc; Predual; CVNA; ProjAlg; ProjLoc (hard)
  • Lemma 3.14: Locale; OpenLocaleMap; CBAlg; LBAlg; MLoc; Predual; CVNA; LocalicLInfinity; Step; ValuationPredual; LocalicIntegral (hard)
  • Lemma 3.17: Locale; OpenLocaleMap; CBAlg; LBAlg; MLoc; Predual; CVNA; ProjAlg; LocalicLInfinity; Step; ValuationPredual; LocalicIntegral; Chi (hard)
  • Lemma 3.19: Locale; OpenLocaleMap; CBAlg; LBAlg; MLoc; Predual; CVNA; ProjAlg; LocalicLInfinity; Step; ValuationPredual; LocalicIntegral; Mu (hard)
  • Theorem 3.20: Locale; OpenLocaleMap; CBAlg; LBAlg; MLoc; Predual; CVNA; ProjAlg; ProjLoc; LocalicLInfinity; Step; ValuationPredual; LocalicIntegral; Chi; Mu (hard)
  • Lemma 4.25: PreEMS; EnhancedCoproduct (source-ambiguity)
  • Lemma 4.26: PreEMS; EMS; EnhancedCoproduct (hard)
  • Proposition 4.41: CBAlg; LBAlg; InducedEnhanced; PreEMS; EMS; QuotientBoolean; EssentialSup; InfiniteMeasure; FiniteMeasure; EssentialMeasure; CompletelyAdditiveMeasure; LocalizableEMS (hard)
  • Proposition 4.42: CBAlg; LBAlg; InducedEnhanced; PreEMS; EMS; QuotientBoolean; EssentialSup; InfiniteMeasure; FiniteMeasure; EssentialMeasure; LocalizableEMS (hard)
  • Proposition 4.45: CBAlg; LBAlg; InducedEnhanced; PreEMS; EMS; QuotientBoolean; InfiniteMeasure; FiniteMeasure; EssentialMeasure; LocalizableEMS (hard)
  • Lemma 4.53: InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; LocallyDetermined; LDEMS (hard)
  • Proposition 4.54: CBAlg; LBAlg; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; LocalizableEMS; StrictLocalizable (hard)
  • Lemma 4.63: InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; LocallyDetermined; LDEMS; CSLEMS (hard)
  • Proposition 4.65: InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; EssentialSup; InfiniteMeasure; FiniteMeasure; StrictLocalizable (hard)
  • Lemma 5.3: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM (hard)
  • Proposition 5.4: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM (hard)
  • Proposition 5.6: Locale; Omega; OpenLocaleMap; StoneanSpace; HStoneanLoc; HStonean; NormalMeasure; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; EssentialMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM (hard)
  • Lemma 5.9: PreEMS; StrictEMS; EMS; QuotientBoolean; PreML; StrictML; WeakML (hard)
  • Lemma 5.11: Locale; CBAlg; LBAlg; MLoc; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; PreML; WeakML; ML (hard)
  • Lemma 5.15: Locale; Omega; Sp; OpenLocaleMap; COpen; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML; Epsilon (hard)
  • Proposition 5.16: Locale; Omega; Sp; OpenLocaleMap; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML; LiftingSection; Eta (hard)
  • Proposition 5.17: Locale; Omega; Sp; OpenLocaleMap; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML; Epsilon; LiftingSection; Eta (hard)
  • Theorem 5.19: Locale; Omega; Sp; OpenLocaleMap; Ideal; CBAlg; StoneanSpace; LBAlg; MLoc; HStoneanLoc; HStonean; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; TopOpen; BaireEnhanced; TM; Spec; PreML; WeakML; ML; Epsilon; LiftingSection; Eta (hard)
  • Remark 2.74: Locale; Sublocale; OpenLocaleMap; COpen; Ideal; CBAlg; LBAlg; MLoc; DoubleNegation; HStoneanLoc (hard)
  • Remark 3.12: Locale; Sp; Ideal; CBAlg; LBAlg; MLoc; Predual; CVNA; ProjAlg; ProjLoc; GelfandSpectrum (hard)
  • Remark 4.8: PreEMS; IncompleteEnhanced; CompletionFunctor (hard)
  • Remark 4.30: CBAlg; LBAlg; InducedEnhanced; PreEMS; EMS; QuotientBoolean; InfiniteMeasure; LocalizableEMS; MeasurableFunctionAlgebra (source-ambiguity)
  • Example 4.60: InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; InfiniteMeasure; FiniteMeasure; StrictLocalizable; CSLEMS; RadonEnhanced (hard)
  • Remark 5.18: Locale; CBAlg; LBAlg; MLoc; InducedEnhanced; PreEMS; EMS; EnhancedCoproduct; QuotientBoolean; InfiniteMeasure; FiniteMeasure; LocalizableEMS; StrictLocalizable; CSLEMS; PreML; WeakML; LocalizedLEMS (hard)
  • Unnumbered result infinite-measure-correspondence: Predual; InducedEnhanced; InfiniteMeasure; InfiniteNormalMeasure; InfiniteValuation (source-ambiguity)

Selected references

  • Gelfand-type duality for commutative von Neumann algebras, arXiv:2005.05284v3, https://arxiv.org/abs/2005.05284v3
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Quantum Information·Captain: Goku

Seminormal forms and Gram determinants for cellular algebrasResearch Paper

Motivation

This paper develops an abstract framework for constructing ``seminormal forms'' for cellular algebras. That is, given a cellular R-algebra A which is equipped with a family of JM-elements we give a general technique for constructing orthogonal bases for A, and for all of its irreducible representations, when the JM-elements separate A. The seminormal forms for A are defined over the field of fractions of R. Significantly, we show that the Gram determinant of each irreducible A-module is equal to a product of certain structure constants coming from the seminormal basis of A. In the non-separated case we use our seminormal forms to give an explicit basis for a block decomposition of A. The appendix, by Marcos Soriano, gives a general construction of a complete set of orthogonal idempotents for an algera starting from a set of elements which act on the algebra in an upper triangular fashion. The appendix shows that constructions with "Jucys-Murphy elements"depend, ultimately, on the Cayley-Hamilton theorem.

This mission is the statement-level formalization of Seminormal forms and Gram determinants for cellular algebras (arXiv:math/0604108v4). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

31 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Gram determinants are products of seminormal structure coefficients (Abstract; Theorem 3.12 determinant consequence, PDF p. 1). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

8 results of the paper are not stated yet, because the library lacks an interface they need:

  • 3.12: The entire numbered mixed-pairing identity (source-ambiguity)
  • 4.4: The modular JM eigenvector clauses (a,b) in the full four-clause proposition (source-ambiguity)
  • 4.5: The actual unital residue-linkage component algebras, restricted cellular data, and algebra direct-sum isomorphism (hard)
  • 4.7: The k-algebra corner and its endomorphism ring on the left ideal A_k G_Gamma (hard)
  • 4.8: The reduced spectral expansion and squarefree minimum polynomial (source-ambiguity)
  • 4.10: Concrete symmetric/type-A, cyclotomic and degenerate Murphy cell towers and their generic DVR lifts (hard)
  • 4.11: Concrete shape residue MULTISETS and same-block/linkage equivalence for the four application families (hard)
  • 4.12: Actual q-Schur and full-weight cyclotomic q-Schur endomorphism algebras, JM operators and block correspondence (hard)

Selected references

  • Seminormal forms and Gram determinants for cellular algebras, arXiv:math/0604108v4, https://arxiv.org/abs/math/0604108v4
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Quantum Information·Captain: Goku

Cyclotomic Birman--Wenzl--Murakami algebras, II: Admissibility Relations and FreenessResearch Paper

Motivation

The cyclotomic Birman-Wenzl-Murakami algebras are quotients of the affine BMW algebras in which the affine generator satisfies a polynomial relation. We study admissibility conditions on the ground ring for these algebras, and show that the algebras defined over an admissible integral ground ring SSS are free SSS--modules and isomorphic to cyclotomic Kauffman tangle algebras. We also determine the representation theory in the generic semisimple case, obtain a recursive formula for the weights of the Markov trace, and give a sufficient condition for semisimplicity.

This mission is the statement-level formalization of Cyclotomic Birman--Wenzl--Murakami algebras, II: Admissibility Relations and Freeness (arXiv:math/0612065v5). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

11 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Conditional expectation of a canonical path idempotent (Lemma 2.19: expectation of a path idempotent, PDF p. 16). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

19 results of the paper are not stated yet, because the library lacks an interface they need:

  • Theorem 6.1; abstract seed: freeness and canonical tangle isomorphism: Cyclotomic Kauffman tangle algebra and canonical BMW comparison map (hard)
  • Lemma 2.15: closure corner and trace identities (corrected typesetting): Normalized geometric closure and its tower embeddings (hard)
  • Lemma 2.16: nonzero tangle generators (ambient level corrected): Concrete tangle generators with scalar-valued normalized trace (hard)
  • Lemma 3.17: generating series, parity expansions and coefficient ring: Compatible rational-function and formal-series model with integral symmetric coefficient subring (hard)
  • Lemma 3.18: universal u-admissible integral domain: Actual universal u-admissible localization with specialization morphisms (hard)
  • Theorem 3.19: universal admissible ring and integral domain: Explicit Laurent polynomial admissibility quotient and torsion-saturated Rbar_0,Rbar_+ (hard)
  • Proposition 3.20: central-series recursion: Central closure moments and formal Laurent series over the commuting tangle coefficient algebra (hard)
  • Section 4 opening: generic representations and simple dimensions: Specific generic coefficient field and canonical multipartition-labelled simple BMW modules (hard)
  • Lemma 4.5: the one-strand algebra and idempotent weights: Geometric one-strand projectors and their canonical closure weights (hard)
  • Theorem 4.8: all seven generic tower assertions: Full concrete generic BMW/KT tower with labelled simple ideals and canonical path idempotents (hard)
  • Lemma 4.9: induction step for JM eigenvalues: Canonical upper-level BMW projectors from the pre-eigenvalue induction construction (hard)
  • Lemma 4.10: adding a box in the rational branching function: Multipartition boundary nodes and generic rational branching function Qtilde (hard)
  • Lemma 4.11: central generating functions on path idempotents: Closure-derived central series acting on the actual generic BMW path projectors (hard)
  • Unnumbered main result: recursive Markov-trace weights, (4.12)-(4.14): Canonical generic Markov trace and multipartition path-weight recursion (hard)
  • Remark 4.12: finite-level sufficient semisimplicity criterion: Nonvacuous finite-level parameter-separation criterion (source-ambiguity)
  • Corollary 4.13: all-level semisimplicity (source ambiguity): Nonvacuous all-level semisimplicity assumptions with root-of-unity control (source-ambiguity)
  • Theorem 5.2: generic BMW dimension: The specific generic fraction field and its actual BMW algebra (hard)
  • Corollary 6.2: trace-preserving expectation and faithful tower maps: Geometric closure transported through the canonical BMW/tangle isomorphism (hard)
  • Remarks 2.10, 2.12 and Section 2.4: ground-ring specialization: Twisted ground-ring specialization and geometric tangle scalar-extension functor (hard)

Selected references

  • Cyclotomic Birman--Wenzl--Murakami algebras, II: Admissibility Relations and Freeness, arXiv:math/0612065v5, https://arxiv.org/abs/math/0612065v5
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Computational GeometryDiscrete GeometryMachine Learning·Captain: mikedeng1

Geometric Deep Learning VI: Cotangent Weights Are Intrinsic, cot ∠uqv = (ℓ²_uq + ℓ²_vq − ℓ²_uv)/(4a_uvq) with Heron's Area a_uvqTextbook

Motivation

Surfaces of three-dimensional objects are stored in computer graphics, vision and geometry processing as triangular meshes: finitely many points glued together by triangles. Geometric deep learning on such data needs a discretisation of the Laplace–Beltrami operator, because spectral filters, diffusion and many graph neural network layers on meshes are built from a Laplacian. The standard choice is the cotangent Laplacian, whose edge weights are cotangents of the angles of the mesh. It goes back to MacNeal's 1949 thesis and was popularised by Pinkall and Polthier (1993) and Meyer, Desbrun, Schröder and Barr (2003).

Bronstein, Bruna, Cohen and Veličković's Geometric Deep Learning (arXiv:2104.13478v2), §4.6, pp. 61–63, introduces this operator and states that, although it is defined through angles, it can be written entirely in terms of edge lengths. This is what makes it intrinsic: invariant under every deformation of the surface that preserves the lengths of the edges. This mission formalizes that claim. The book numbers no theorems, lemmas or definitions, so every item is cited by section, equation and printed page.

Setting

A mesh on the nodes 1,…,n1,\dots,n1,…,n is a finite set F\mathcal FF of ordered triplets (u,v,q)(u,v,q)(u,v,q) of distinct nodes, the faces; the order of a triplet is the orientation of the face, and each triangle occurs once. As assumed in §4.6, each edge belongs to two faces and the faces incident to each node form a single loop. The nodes are placed at points x1,…,xn\mathbf x_1,\dots,\mathbf x_nx1​,…,xn​ of a Euclidean space (the book's R3\mathbb R^3R3). The mesh carries the metric

ℓuv=∥xu−xv∥.\ell_{uv} = \|\mathbf x_u - \mathbf x_v\|.ℓuv​=∥xu​−xv​∥.

A quantity is intrinsic if it can be expressed through ℓ\ellℓ alone.

For a face with vertices u,v,qu,v,qu,v,q, the angle ∠uqv\angle uqv∠uqv is the angle at xq\mathbf x_qxq​ between the directions to xu\mathbf x_uxu​ and xv\mathbf x_vxv​; it is the angle opposite the edge (u,v)(u,v)(u,v). The area of the face is auvq=12 ℓuq ℓvqsin⁡∠uqva_{uvq} = \frac12\,\ell_{uq}\,\ell_{vq}\sin\angle uqvauvq​=21​ℓuq​ℓvq​sin∠uqv. The face is non-degenerate when its three vertices are affinely independent, that is, not collinear.

The local area element of a node is au=13∑f∋uafa_u = \frac13\sum_{f\ni u} a_fau​=31​∑f∋u​af​, one third of the total area of the faces incident to uuu. For an interior edge (u,v)(u,v)(u,v) shared by exactly two faces (u,q,v)(u,q,v)(u,q,v) and (u,p,v)(u,p,v)(u,p,v), the cotangent weight of equation (25) is

wuv=cot⁡∠uqv+cot⁡∠upv2au.w_{uv} = \frac{\cot\angle uqv + \cot\angle upv}{2a_u}.wuv​=2au​cot∠uqv+cot∠upv​.

In general, wuvw_{uv}wuv​ sums the cotangents of the angles opposite (u,v)(u,v)(u,v) over the faces containing that edge. The Laplacian of equation (24) is the n×nn\times nn×n matrix Δ=D−W\boldsymbol\Delta = \mathbf D - \mathbf WΔ=D−W, where W\mathbf WW holds the weights off the diagonal and D=diag⁡(d1,…,dn)\mathbf D = \operatorname{diag}(d_1,\dots,d_n)D=diag(d1​,…,dn​) with du=∑vwuvd_u = \sum_v w_{uv}du​=∑v​wuv​.

Heron's expression of three lengths, with semiperimeter suvq=12(ℓuv+ℓuq+ℓvq)s_{uvq} = \frac12(\ell_{uv}+\ell_{uq}+\ell_{vq})suvq​=21​(ℓuv​+ℓuq​+ℓvq​), is

suvq(suvq−ℓuv)(suvq−ℓvq)(suvq−ℓuq).\sqrt{s_{uvq}(s_{uvq}-\ell_{uv})(s_{uvq}-\ell_{vq})(s_{uvq}-\ell_{uq})}.suvq​(suvq​−ℓuv​)(suvq​−ℓvq​)(suvq​−ℓuq​)​.

Formalization targets

Goal: the cotangent weights are intrinsic (p. 63)

For an interior edge (u,v)(u,v)(u,v) whose two faces (u,q,v)(u,q,v)(u,q,v) and (u,p,v)(u,p,v)(u,p,v) are non-degenerate, with auvqa_{uvq}auvq​ and auvpa_{uvp}auvp​ given by Heron's expression,

cot⁡∠uqv+cot⁡∠upv2=−ℓuv2+ℓvq2+ℓuq28 auvq+−ℓuv2+ℓvp2+ℓup28 auvp,\frac{\cot\angle uqv + \cot\angle upv}{2} = \frac{-\ell_{uv}^2+\ell_{vq}^2+\ell_{uq}^2}{8\,a_{uvq}} + \frac{-\ell_{uv}^2+\ell_{vp}^2+\ell_{up}^2}{8\,a_{uvp}},2cot∠uqv+cot∠upv​=8auvq​−ℓuv2​+ℓvq2​+ℓuq2​​+8auvp​−ℓuv2​+ℓvp2​+ℓup2​​,

and the weight wuvw_{uv}wuv​ of (25) is this right-hand side divided by aua_uau​.

The printed display sets the right-hand side equal to wuvw_{uv}wuv​ itself. That omits the factor 1/au1/a_u1/au​ of (25), so the goal states the corrected identity.

Milestones

  1. Triangle inequality (p. 61): on every face, ℓuv≤ℓuq+ℓvq\ell_{uv}\le\ell_{uq}+\ell_{vq}ℓuv​≤ℓuq​+ℓvq​ for every combination of its edges.
  2. Heron's formula (p. 63): auvq=suvq(suvq−ℓuv)(suvq−ℓvq)(suvq−ℓuq)a_{uvq} = \sqrt{s_{uvq}(s_{uvq}-\ell_{uv})(s_{uvq}-\ell_{vq})(s_{uvq}-\ell_{uq})}auvq​=suvq​(suvq​−ℓuv​)(suvq​−ℓvq​)(suvq​−ℓuq​)​ for every triangle.
  3. One face's term (p. 63): for a non-degenerate triangle, cot⁡∠uqv=(−ℓuv2+ℓvq2+ℓuq2)/(4auvq)\cot\angle uqv = (-\ell_{uv}^2+\ell_{vq}^2+\ell_{uq}^2)/(4a_{uvq})cot∠uqv=(−ℓuv2​+ℓvq2​+ℓuq2​)/(4auvq​), so each summand of the display is half a cotangent.
  4. Isometry invariance (p. 63): two embeddings of a mesh with the same edge lengths on every face have the same cotangent Laplacian.

Companion (corrected)

The Laplacian with the unnormalised weights (cot⁡∠uqv+cot⁡∠upv)/2(\cot\angle uqv+\cot\angle upv)/2(cot∠uqv+cot∠upv)/2 is symmetric and positive semidefinite for every manifold mesh of non-degenerate triangles (p. 63, after Wardetzky et al. 2007).

Significance

The intrinsic form of the cotangent weights is what makes the cotangent Laplacian, and everything derived from it, invariant under isometric deformations of a mesh. This includes its eigenvalues and eigenvectors, and hence spectral descriptors, heat kernels and spectral convolutions. A bent or articulated shape and its rest pose then give the same operator, which is the reason for the operator's use in shape analysis and in geometric deep learning on meshes.

The individual facts (the law of cosines, Heron's formula, the Dirichlet-energy form of the cotangent Laplacian) are classical and proved in the literature. None of them is stated on the platform for meshes. Mathlib has the law of cosines (EuclideanGeometry.law_cos) but Heron's formula only in its non-importable Archive, and it has no mesh Laplacian. This mission adds a mesh layer to the platform: triangulated faces, edge lengths, face areas, local area elements, the cotangent weights (25) and the Laplacian (24). It also corrects two slips on p. 63: the normalisation in the intrinsic display, and the symmetry claim for (25)'s weights.

Difficulty

The per-face identities are classical trigonometry. The difficulty is not the trigonometry but connecting an extrinsic quantity, an angle between vectors of the ambient space, to a square root of a polynomial in lengths, with the sign under the square root controlled for every triangle, degenerate ones included.

The mesh-level statements need bookkeeping that the page leaves implicit. A face is stored with one orientation, so an edge (u,v)(u,v)(u,v) can appear as (v,u)(v,u)(v,u) inside it, and the angle opposite must be found at whichever vertex is left. The sum defining wuvw_{uv}wuv​ ranges over all faces, and the hypothesis that (u,v)(u,v)(u,v) is interior has to reduce it to exactly two terms. Isometry invariance must also cover degenerate faces, where Lean assigns junk values to angles. Positive semidefiniteness is the hardest item: obtuse angles have negative cotangents, so the weights can be negative and the usual argument for graph Laplacians with nonnegative weights does not apply.

Formalization scope

Nodes are Fin n. The embedding x : Fin n → P takes values in an arbitrary Euclidean affine space P (a real inner product space torsor), of which R3\mathbb R^3R3 is an instance. A mesh (TriMesh n) is a Finset of ordered triplets with three distinct nodes per face and no triangle listed twice. The mesh-level theorems assume IsManifoldMesh: a nonempty face set, two faces per edge, and a connected loop of incident faces at each node. Angles are Mathlib's EuclideanGeometry.angle, with the vertex in the middle argument, and cot⁡\cotcot is Real.cot. The face area is defined geometrically as 12ℓuqℓvqsin⁡∠uqv\frac12\ell_{uq}\ell_{vq}\sin\angle uqv21​ℓuq​ℓvq​sin∠uqv and not by Heron's formula; with the latter, Heron's formula and the intrinsic claim would hold by definition and lose their content. The local area element aua_uau​ sums the areas of the faces incident to uuu, each counted once. This is the book's formula 13∑v,q:(u,v,q)∈Fauvq\frac13\sum_{v,q:(u,v,q)\in\mathcal F}a_{uvq}31​∑v,q:(u,v,q)∈F​auvq​ read over unoriented faces.

The book assumes non-degenerate triangles throughout. Lean's cot⁡\cotcot returns the junk value 000 at the angles 000 and π\piπ, and the Heron area of a degenerate triangle is 000. So the cotangent identities assume that the triangles in their denominators are non-degenerate (affinely independent vertices). The goal assumes this for the two faces of the edge, and the companion for every face. Heron's formula and isometry invariance also hold for degenerate triples. Every mesh-level theorem carries the standing manifold-mesh condition of pp. 61–62; the goal additionally identifies the two faces of its chosen interior edge.

Contributions welcome: proofs of Heron's formula for points of a Euclidean space, of the per-face cotangent identity, and of the per-face positive semidefinite form. These three are reusable for any discrete differential geometry on the platform.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen, P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint, 2021. https://arxiv.org/abs/2104.13478v2
  • U. Pinkall, K. Polthier, Computing discrete minimal surfaces and their conjugates, Experimental Mathematics 2(1), 1993. https://doi.org/10.1080/10586458.1993.10504266
  • M. Meyer, M. Desbrun, P. Schröder, A. H. Barr, Discrete differential-geometry operators for triangulated 2-manifolds, Visualization and Mathematics III, Springer, 2003. https://doi.org/10.1007/978-3-662-05105-4_2
  • M. Wardetzky, S. Mathur, F. Kälberer, E. Grinspun, Discrete Laplace operators: no free lunch, Symposium on Geometry Processing, 2007. https://doi.org/10.2312/SGP/SGP07/033-037
  • Y. Wang, J. Solomon, Intrinsic and extrinsic operators for shape analysis, Handbook of Numerical Analysis 20, 2019. https://doi.org/10.1016/bs.hna.2019.08.003
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Group TheoryMachine LearningRepresentation Theory·Captain: mikedeng1

Geometric Deep Learning I: A Linear G-Invariant Function of a Signal Depends on It Only Through the Group Average Ax = (1/μ(G)) ∫ g.x dμ(g)Textbook

Symmetry as a design principle

Geometric deep learning is the programme, set out by Bronstein, Bruna, Cohen and Veličković in Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges (arXiv:2104.13478v2, 2021), of deriving neural network architectures from the symmetries of the domain on which the data live. Convolutional networks on images, permutation-invariant networks on sets, graph neural networks and equivariant networks for molecules are presented there as instances of one template. Chapter 3 of the book, Geometric Priors, gives that template: it fixes what a symmetry of a signal is, what it means for a function to respect it, and how invariant functions are assembled from simpler blocks. This mission formalizes the definitions and the elementary claims of Chapter 3. Its goal is the observation the book uses to explain why such networks must be non-linear.

The book numbers no theorem, lemma or definition. Its only labels are the sections, the equations (1)–(53) and the figures. Every item of this mission is therefore cited by section, equation number (where there is one) and printed page of the arXiv v2 text; a margin note is cited as "side-note, p. n".

Setting

A domain is a set Ω\OmegaΩ. A signal on Ω\OmegaΩ with values in a set of channels CCC is a function x:Ω→Cx : \Omega \to Cx:Ω→C; the signals form the space X(Ω,C)X(\Omega, C)X(Ω,C) (equation (1)), written X(Ω)X(\Omega)X(Ω) when C=RC = \mathbb RC=R.

A group G\mathfrak GG acts on Ω\OmegaΩ through a map (g,u)↦g.u(\mathfrak g, u) \mapsto \mathfrak g . u(g,u)↦g.u with g.(h.u)=(gh).u\mathfrak g . (\mathfrak h . u) = (\mathfrak g \mathfrak h) . ug.(h.u)=(gh).u. It then acts on signals by equation (3):

(g.x)(u)=x(g−1u).(\mathfrak g . x)(u) = x(\mathfrak g^{-1} u).(g.x)(u)=x(g−1u).

On real signals this action is linear, so ρ(g)x=g.x\rho(\mathfrak g) x = \mathfrak g . xρ(g)x=g.x defines a representation ρ\rhoρ of G\mathfrak GG on X(Ω)X(\Omega)X(Ω).

A function f:X(Ω,C)→Yf : X(\Omega, C) \to Yf:X(Ω,C)→Y is G\mathfrak GG-invariant if f(g.x)=f(x)f(\mathfrak g . x) = f(x)f(g.x)=f(x) for all g\mathfrak gg and xxx. A map B:X(Ω,C)→X(Ω′,C′)B : X(\Omega, C) \to X(\Omega', C')B:X(Ω,C)→X(Ω′,C′) between signal spaces on which G\mathfrak GG acts is G\mathfrak GG-equivariant if B(g.x)=g.B(x)B(\mathfrak g . x) = \mathfrak g . B(x)B(g.x)=g.B(x). A map σ:C→C′\sigma : C \to C'σ:C→C′ acts on signals element-wise, (σ(x))(u)=σ(x(u))(\boldsymbol\sigma(x))(u) = \sigma(x(u))(σ(x))(u)=σ(x(u)).

For a measure μ\muμ on G\mathfrak GG with 0<μ(G)<∞0 < \mu(\mathfrak G) < \infty0<μ(G)<∞, the G\mathfrak GG-average of a real signal is

Ax=1μ(G)∫G(g.x) dμ(g).A x = \frac{1}{\mu(\mathfrak G)} \int_{\mathfrak G} (\mathfrak g . x)\, \mathrm d\mu(\mathfrak g).Ax=μ(G)1​∫G​(g.x)dμ(g).

The book takes μ\muμ to be the Haar measure of the group.

The metric distortion of a map η\etaη between metric spaces is dis⁡(η)=sup⁡u,v∣d(η(u),η(v))−d(u,v)∣\operatorname{dis}(\eta) = \sup_{u,v} |d(\eta(u), \eta(v)) - d(u, v)|dis(η)=supu,v​∣d(η(u),η(v))−d(u,v)∣ (§4.4, p. 51). A self-map τ\tauτ with distortion at most ε\varepsilonε is an ε\varepsilonε-isometry.

The Geometric Deep Learning Blueprint (§3.5, p. 29) builds functions

f=A∘σJ∘BJ∘PJ−1∘⋯∘P1∘σ1∘B1f = A \circ \boldsymbol\sigma_J \circ B_J \circ P_{J-1} \circ \cdots \circ P_1 \circ \boldsymbol\sigma_1 \circ B_1f=A∘σJ​∘BJ​∘PJ−1​∘⋯∘P1​∘σ1​∘B1​

from equivariant linear layers BjB_jBj​, element-wise nonlinearities σj\boldsymbol\sigma_jσj​, poolings PjP_jPj​ onto coarser domains, and an invariant global pooling AAA.

Formalization targets

Goal: linear invariants see only the average (§3.5, p. 27)

For a finite domain Ω\OmegaΩ, a finite nonzero measure μ\muμ on G\mathfrak GG, and a linear G\mathfrak GG-invariant map fff from X(Ω)X(\Omega)X(Ω) into a real Banach space, for every signal xxx,

f(x)=1μ(G)∫Gf(g.x) dμ(g)=f ⁣(1μ(G)∫G(g.x) dμ(g))=f(Ax).f(x) = \frac{1}{\mu(\mathfrak G)} \int_{\mathfrak G} f(\mathfrak g . x)\, \mathrm d\mu(\mathfrak g) = f\!\left( \frac{1}{\mu(\mathfrak G)} \int_{\mathfrak G} (\mathfrak g . x)\, \mathrm d\mu(\mathfrak g) \right) = f(Ax).f(x)=μ(G)1​∫G​f(g.x)dμ(g)=f(μ(G)1​∫G​(g.x)dμ(g))=f(Ax).

A linear invariant therefore depends on xxx only through AxAxAx.

Milestones, in attack order

  1. The action (3) is a group action: g.(h.x)=(gh).x\mathfrak g . (\mathfrak h . x) = (\mathfrak g\mathfrak h) . xg.(h.x)=(gh).x (p. 14).
  2. It is linear: g.(αx+βx′)=α(g.x)+β(g.x′)\mathfrak g . (\alpha x + \beta x') = \alpha(\mathfrak g . x) + \beta(\mathfrak g . x')g.(αx+βx′)=α(g.x)+β(g.x′) (p. 15).
  3. It is a representation: ρ(g)(ρ(h)x)=ρ(gh)x\rho(\mathfrak g)(\rho(\mathfrak h)x) = \rho(\mathfrak g\mathfrak h)xρ(g)(ρ(h)x)=ρ(gh)x (p. 15).
  4. Two ε\varepsilonε-isometries compose to a 2ε2\varepsilon2ε-isometry, and ε\varepsilonε-isometries are not closed under composition (side-note, p. 20).
  5. U=σ∘BU = \boldsymbol\sigma \circ BU=σ∘B is equivariant for equivariant BBB and any element-wise σ\sigmaσ (p. 27).
  6. The G\mathfrak GG-average is invariant, so A∘UA \circ UA∘U is invariant (p. 27).
  7. The blueprint fff is G\mathfrak GG-invariant (p. 29).

Companion: the Fourier modulus (§3.4, p. 25)

With x^(ξ)=∫x(u)e−iξu du\hat x(\xi) = \int x(u) e^{-\mathrm i\xi u}\,\mathrm dux^(ξ)=∫x(u)e−iξudu and (Svx)(u)=x(u−v)(S_v x)(u) = x(u - v)(Sv​x)(u)=x(u−v), Svx^(ξ)=e−iξvx^(ξ)\widehat{S_v x}(\xi) = e^{-\mathrm i \xi v}\hat x(\xi)Sv​x​(ξ)=e−iξvx^(ξ), so ∣Svx^∣=∣x^∣|\widehat{S_v x}| = |\hat x|∣Sv​x​∣=∣x^∣.

Significance

The goal is the book's reason for non-linearity. Linear invariant models collapse to functions of the group average, so they cannot tell apart two images with the same mean colour. Expressive invariant models must interleave equivariant linear layers with non-linear maps. Milestones 5–7 are the positive half of the same argument: element-wise nonlinearities keep equivariance, the average turns equivariance into invariance, and stacking such blocks gives the blueprint that the later chapters instantiate on grids, groups, graphs and manifolds. Milestone 4 is the book's reason for leaving exact symmetry behind: small deformations do not form a group, so it replaces invariance to deformations by stability to them.

Each claim of the chapter is proved in one or two lines on the page, and none is new mathematics. What a formalization adds is the precise setting in which they hold. The book names the Haar measure but its identity needs no invariance of μ\muμ; the average's invariance needs right invariance, which the page does not state; and the printed blueprint is invariant only if the poolings are equivariant. As far as a search of the platform and Mathlib shows, none of these statements has a machine-checked proof. The definitions here (the action on signals, invariance, equivariance, the average, the blueprint) are reusable by every later mission of this series.

Difficulty

The obvious argument for the goal pulls fff through the integral, which uses linearity in the form "a continuous linear map commutes with the Bochner integral". That needs continuity of fff and integrability of g↦g.x\mathfrak g \mapsto \mathfrak g . xg↦g.x, and neither is stated on the page. On a finite domain both follow from the setting, finite dimension for continuity and boundedness with measurability for integrability. The measurability of g↦g−1.u\mathfrak g \mapsto \mathfrak g^{-1} . ug↦g−1.u has to be assumed of the group and the action.

For the average's invariance, the substitution g↦gh\mathfrak g \mapsto \mathfrak g\mathfrak hg↦gh is valid only for a right-invariant measure. For the blueprint, the composite's invariance fails for a non-equivariant pooling, so the box's claim is false as printed. For the ε\varepsilonε-isometries, the subtle half is the negative one: exhibiting a deformation that is an ε\varepsilonε-isometry while its square is not.

Formalization scope

  • Signals are functions Ω → C. The goal and the average use real signals on a finite domain ([Fintype Ω]), following the book's side-note on p. 15 that one must always discretise to a finite grid in practice; the other milestones allow any domain and any channel types.
  • The action (3) is a function act g x := fun u => x (g⁻¹ • u) for [MulAction G Ω], not a MulAction instance on Ω → C.
  • The measure is any μ with [IsFiniteMeasure μ] and μ ≠ 0. Without those hypotheses Lean's (μ univ).toReal⁻¹ would be 000 and the goal false. The goal assumes no invariance of μ. Milestone 6 adds [μ.IsMulRightInvariant], which the Haar measure of a compact group satisfies.
  • Measurability: [MeasurableInv G], [MeasurableSMul G Ω] and the discrete σ-algebra on Ω; integrability of g ↦ g.x is a consequence, not a hypothesis. A finite group with the counting measure and a compact group with its Haar measure both fit.
  • The blueprint is indexed from 000 to n=J−1n = J - 1n=J−1. A single group acts on all domains, and the poolings are assumed equivariant (a correction of the printed box, disclosed in the statement). The box's remark that different blocks may use different groups is not formalized.
  • ε\varepsilonε-isometries are defined pointwise (∣d(τu,τv)−d(u,v)∣≤ε|d(\tau u, \tau v) - d(u,v)| \le \varepsilon∣d(τu,τv)−d(u,v)∣≤ε for all u,vu, vu,v), avoiding a real supremum that would be 000 on an unbounded set. Non-closure is witnessed on R\mathbb RR by a continuous bijection.
  • The Fourier transform of the companion is the book's ∫x(u)e−iξu du\int x(u)e^{-\mathrm i\xi u}\,\mathrm du∫x(u)e−iξudu (no 2π2\pi2π), a Bochner integral over R\mathbb RR.

The goal cannot be satisfied trivially. groupAverage is defined from μ and the action alone, the goal quantifies over every linear invariant f, and the measure hypotheses exclude the degenerate case in which the average is 000. Proofs, finite-sum encodings of the average, and versions for complex or vector-valued channels are welcome.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen, P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint, 2021. https://arxiv.org/abs/2104.13478v2
  • S. Mallat, Group Invariant Scattering, Communications on Pure and Applied Mathematics 65(10), 2012. https://doi.org/10.1002/cpa.21413
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CombinatoricsLinear algebraMachine Learning·Captain: mikedeng1

Geometric Deep Learning II: Every Linear Permutation-Equivariant Map on ℝⁿ Is a Linear Combination of the Identity and the Averaging Map (1/n)𝟙𝟙ᵀTextbook

Motivation

Many learning problems take an unordered collection as input: the points of a point cloud, the particles of a physical system, the atoms of a molecule, the nodes of a graph. Storing such data in memory fixes an order of the elements, but the order carries no information, and a model whose output changes when the rows of its input are shuffled is answering a different question from the one posed. Bronstein, Bruna, Cohen and Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges (arXiv:2104.13478v2, 2021), §4.1, make this the first instance of their blueprint: the domain is a set (or a graph) of nnn nodes, and the symmetry group is the symmetric group Σn\Sigma_nΣn​ of all reorderings.

Two architectures used in practice follow this pattern. Deep Sets (Zaheer et al., NeurIPS 2017) and PointNets (Qi et al., CVPR 2017) process sets; message-passing graph neural networks process graphs. The design question in both cases is which layers respect the symmetry. For linear layers the question has a complete answer, and the answer determines the layer used by Deep Sets. For graphs, Maron, Ben-Hamu, Shamir and Lipman (2018) counted the linear layers acting on adjacency matrices.

Setting

A set of nnn nodes V={1,…,n}\mathcal V=\{1,\dots,n\}V={1,…,n} carries node features xu∈Rd\mathbf x_u\in\mathbb R^dxu​∈Rd, stacked as the rows of a matrix X∈Rn×d\mathbf X\in\mathbb R^{n\times d}X∈Rn×d. A graph adds an adjacency matrix A∈Rn×n\mathbf A\in\mathbb R^{n\times n}A∈Rn×n, eq. (8), whose nonzero entries are the edges.

A permutation σ∈Σn\sigma\in\Sigma_nσ∈Σn​ acts through its permutation matrix P\mathbf PP by reordering rows: row uuu of PX\mathbf P\mathbf XPX is row σ−1(u)\sigma^{-1}(u)σ−1(u) of X\mathbf XX. On adjacency matrices it acts by A↦PAP⊤\mathbf A\mapsto\mathbf P\mathbf A\mathbf P^\topA↦PAP⊤, reordering rows and columns together.

A function fff is permutation invariant if f(PX)=f(X)f(\mathbf P\mathbf X)=f(\mathbf X)f(PX)=f(X) for every permutation matrix P\mathbf PP, and a matrix-valued function F\mathbf FF is permutation equivariant if F(PX)=PF(X)\mathbf F(\mathbf P\mathbf X)=\mathbf P\mathbf F(\mathbf X)F(PX)=PF(X). On graphs the book's definitions (9) and (10) are

f(PX,PAP⊤)=f(X,A)(9),F(PX,PAP⊤)=PF(X,A)(10),f(\mathbf P\mathbf X,\mathbf P\mathbf A\mathbf P^\top)=f(\mathbf X,\mathbf A)\quad(9),\qquad \mathbf F(\mathbf P\mathbf X,\mathbf P\mathbf A\mathbf P^\top)=\mathbf P\mathbf F(\mathbf X,\mathbf A)\quad(10),f(PX,PAP⊤)=f(X,A)(9),F(PX,PAP⊤)=PF(X,A)(10),

for any permutation matrix P\mathbf PP.

The section's constructions are the sum readout f(X)=ϕ(∑u∈Vψ(xu))f(\mathbf X)=\phi\big(\sum_{u\in\mathcal V}\psi(\mathbf x_u)\big)f(X)=ϕ(∑u∈V​ψ(xu​)) (6); the shared node-wise linear map FΘ(X)=XΘ\mathbf F_{\boldsymbol\Theta}(\mathbf X)=\mathbf X\boldsymbol\ThetaFΘ​(X)=XΘ (7); the neighbourhood Nu={v:(u,v)∈E or (v,u)∈E}\mathcal N_u=\{v:(u,v)\in\mathcal E\text{ or }(v,u)\in\mathcal E\}Nu​={v:(u,v)∈E or (v,u)∈E} (11) and the multiset of neighbourhood features XNu={ ⁣{xv:v∈Nu} ⁣}\mathbf X_{\mathcal N_u}=\{\!\{\mathbf x_v:v\in\mathcal N_u\}\!\}XNu​​={{xv​:v∈Nu​}} (12); and the local layer whose uuu-th row is ϕ(xu,XNu)\phi(\mathbf x_u,\mathbf X_{\mathcal N_u})ϕ(xu​,XNu​​) (13). For one feature channel the two linear generators are the identity F1x=x\mathbf F_1x=xF1​x=x and the average F2x=1n11⊤x\mathbf F_2x=\tfrac1n\mathbf 1\mathbf 1^\top xF2​x=n1​11⊤x, every entry of which is the mean 1n∑uxu\tfrac1n\sum_u x_un1​∑u​xu​.

The book numbers no theorems, lemmas or definitions; every item of this mission is cited by section, equation number and printed page.

Formalization targets

Goal: linear equivariant maps on one channel

For n≥1n\ge1n≥1 and a linear map F:Rn→Rn\mathbf F:\mathbb R^n\to\mathbb R^nF:Rn→Rn,

(∀ P, ∀x: FPx=PFx)  ⟺  ∃ α,β∈R  ∀x: Fx=α x+β 1n11⊤x.\big(\forall\,\mathbf P,\ \forall x:\ \mathbf F\mathbf P x=\mathbf P\mathbf F x\big)\iff \exists\,\alpha,\beta\in\mathbb R\ \ \forall x:\ \mathbf F x=\alpha\,x+\beta\,\tfrac1n\mathbf 1\mathbf 1^\top x .(∀P, ∀x: FPx=PFx)⟺∃α,β∈R  ∀x: Fx=αx+βn1​11⊤x.

This is the book's sentence on p. 33: any linear equivariant "can be written as a linear combination of two generators, the identity … and the average". Both directions are stated; the content is the "only if" direction.

Milestones

  1. The sum readout (6) is permutation invariant (p. 32).
  2. The node-wise linear map (7) is permutation equivariant, with rows hu=Θ⊤xu\mathbf h_u=\boldsymbol\Theta^\top\mathbf x_uhu​=Θ⊤xu​ (p. 33).
  3. The local layer (13) satisfies (10) whenever ϕ\phiϕ is invariant to the order of the neighbourhood (p. 34).
  4. Invariant and equivariant functions give identical outputs on isomorphic graphs (p. 35).
  5. On the complete graph A=11⊤\mathbf A=\mathbf 1\mathbf 1^\topA=11⊤, the aggregate ⨁v∈Vψ(xv)\bigoplus_{v\in\mathcal V}\psi(\mathbf x_v)⨁v∈V​ψ(xv​) is the same at every node (§5.4, p. 81).

Stronger statements

  • Several channels (corrected). A linear F:Rn×d→Rn×d′\mathbf F:\mathbb R^{n\times d}\to\mathbb R^{n\times d'}F:Rn×d→Rn×d′ is permutation equivariant iff F(X)=XΘ1+1n11⊤XΘ2\mathbf F(\mathbf X)=\mathbf X\boldsymbol\Theta_1+\tfrac1n\mathbf 1\mathbf 1^\top\mathbf X\boldsymbol\Theta_2F(X)=XΘ1​+n1​11⊤XΘ2​.
  • Adjacency matrices (Maron et al., corrected). For n≥4n\ge4n≥4, the linear maps L:Rn×n→Rn×nL:\mathbb R^{n\times n}\to\mathbb R^{n\times n}L:Rn×n→Rn×n with L(PAP⊤)=PL(A)P⊤L(\mathbf P\mathbf A\mathbf P^\top)=\mathbf P L(\mathbf A)\mathbf P^\topL(PAP⊤)=PL(A)P⊤ form a space of dimension 15=B415=B_415=B4​.

Significance

The result. The goal classifies the linear layers of a set network. Any equivariant linear layer on scalar node features mixes each node's own value with the mean of all values, and nothing else; with several channels the two scalars become two weight matrices, which is exactly the Deep Sets layer. Read the other way, the theorem says that the commutant of the permutation representation of Σn\Sigma_nΣn​ on Rn\mathbb R^nRn is two-dimensional (for n≥2n\ge2n≥2), the algebraic fact behind the decomposition Rn=span(1)⊕1⊥\mathbb R^n=\mathrm{span}(\mathbf 1)\oplus\mathbf 1^\perpRn=span(1)⊕1⊥ into two irreducible pieces. The Maron et al. count does the same for layers acting on adjacency matrices and fixes the size of the parameter space of invariant graph networks. The milestones give the elementary invariance and equivariance facts on which the graph-network chapter rests, including the constant aggregate on a complete graph.

Formalizing it. All results here are classical and proved on paper. None is formalized on Prove2Me, and Mathlib has no statement about the commutant of the permutation representation or about equivariant layers on sets. The mission produces a vocabulary of permutation actions on feature and adjacency matrices, and the invariance and equivariance definitions (9)–(10), that later missions of this series (the WL comparison, the E(3)-equivariant layer) also use. Two of the book's printed claims need correction to be true, and the formal statements record the corrected versions.

Difficulty

The milestones are short reindexing arguments; the work is in choosing encodings that keep them faithful. The goal's "if" direction is a one-line computation. The "only if" direction is where an argument is needed: equivariance under all of Σn\Sigma_nΣn​ must force the matrix of F\mathbf FF to have one value on the diagonal and one value off it. Equivariance under a smaller group does not suffice: commuting with the cyclic shift alone gives all circulant matrices, an nnn-dimensional space, so the argument must use permutations beyond the shifts. The channel version adds a tensor-product layer to the same argument. The Maron et al. count is a dimension statement, so it needs both a spanning family and its independence, and the count is sensitive to nnn: for n<4n<4n<4 the dimension is strictly smaller than 15, so any argument must use n≥4n\ge4n≥4 somewhere.

Formalization scope

Node features are Matrix (Fin n) (Fin d) ℝ (rows are nodes); a single channel is Fin n → ℝ. A permutation is σ : Equiv.Perm (Fin n), acting by X.submatrix σ.symm id (row uuu of PX\mathbf P\mathbf XPX is row σ−1(u)\sigma^{-1}(u)σ−1(u)) and on adjacency matrices by A.submatrix σ.symm σ.symm; this one convention is used in every statement. Adjacency matrices are real; the edge set is the set of nonzero entries, which for the book's 0/1 matrix (8) is its edge set and also admits weighted graphs. The function ϕ\phiϕ of (13) and the aggregator ⨁\bigoplus⨁ of §5.4 take a Multiset, so their invariance to the order of the neighbours holds by construction. The average 1n11⊤\tfrac1n\mathbf 1\mathbf 1^\topn1​11⊤ is written with (n:R)−1(n:\mathbb R)^{-1}(n:R)−1, and the goal and channel version assume 0<n0<n0<n. Equivariance quantifies over every permutation of Σn\Sigma_nΣn​, never a generating subset. The complete-graph item states the identical-aggregate clause of §5.4. The page's later claim of equal expressive power across inputs is false: with n=2n=2n=2, ψ(x)=x\psi(x)=xψ(x)=x, ⨁=∑\bigoplus=\sum⨁=∑, and ϕ(x,s)=s\phi(x,s)=sϕ(x,s)=s, changing x2x_2x2​ changes h1h_1h1​ while x1x_1x1​ stays fixed, which no node-only map can reproduce.

A trivializing formalization is ruled out: "equivariant" is the commutation property itself, never defined as "of the form αI+β1n11⊤\alpha\mathbf I+\beta\tfrac1n\mathbf 1\mathbf 1^\topαI+βn1​11⊤".

Two printed claims are corrected. On p. 33 the two-generator form is stated for matrices X\mathbf XX with ddd channels; it is false for d>1d>1d>1 (the map X↦XΘ\mathbf X\mapsto\mathbf X\boldsymbol\ThetaX↦XΘ of (7) is a counterexample), so the goal is single-channel and the multi-channel statement uses weight matrices. On p. 34 the fifteen generators are said to be independent of nnn; the dimension is 1, 8 and 14 for n=1,2,3n=1,2,3n=1,2,3, so that item assumes n≥4n\ge4n≥4, and it is stated for adjacency-to-adjacency maps as the side-note on p. 33 specifies.

The development needs Mathlib's Equiv.Perm, Matrix.submatrix, Finset sums and reindexing (Equiv.sum_comp), Multiset.map, and Module.finrank. Proofs of the commutant statements, of the multi-channel version and of the dimension count are welcome; the permutation-action and invariance lemmas proved along the way are reusable by any later development on graph networks.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen, P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint, 2021. https://arxiv.org/abs/2104.13478v2
  • M. Zaheer, S. Kottur, S. Ravanbakhsh, B. Póczos, R. Salakhutdinov, A. Smola, Deep Sets, NeurIPS, 2017. https://arxiv.org/abs/1703.06114
  • H. Maron, H. Ben-Hamu, N. Shamir, Y. Lipman, Invariant and Equivariant Graph Networks, ICLR, 2019. https://arxiv.org/abs/1812.09902
  • C. R. Qi, H. Su, K. Mo, L. J. Guibas, PointNet: Deep Learning on Point Sets for 3D Classification and Segmentation, CVPR, 2017. https://arxiv.org/abs/1612.00593
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Group TheoryHarmonic AnalysisMachine Learning·Captain: mikedeng1

Geometric Deep Learning IV: Group Convolution (x ⋆ θ)(g) = ⟨x, ρ(g)θ⟩ Against an Invariant Measure Is Equivariant, (ρ(h)x) ⋆ θ = ρ(h)(x ⋆ θ)Textbook

Motivation

Convolutional networks use the same filter at many locations. A shift of the input then shifts the output in a predictable way, allowing one set of filter coefficients to serve every location. Bronstein, Bruna, Cohen and Veličković, Geometric Deep Learning, §4.3, pp. 40–43 ask how this idea extends when the transformations form a group and the signal domain need not be the group itself. A grid and its cyclic shifts are one example; a sphere and its rotation group are another. In the latter example, a rotation is an output index even though it is not a point of the sphere. This distinction matters when a second convolutional layer processes the first layer's output.

The chapter places this construction within its general account of geometric deep learning: symmetries specify how inputs transform, and a compatible map should transform its outputs in a corresponding way. Here the concrete question is whether the integral defining group convolution has that compatibility. The source calls this property equivariance and gives it immediately after equation (14). The book numbers equations but no theorems, lemmas, propositions, or definitions, so the items below are cited by section, equation, and printed page.

Setting

Let GGG be a group acting transitively on a domain Ω\OmegaΩ; write g⋅ug\cdot ug⋅u for the image of u∈Ωu\in\Omegau∈Ω. The section makes this homogeneous-domain assumption explicit on p. 43. A signal is a scalar function x:Ω→Rx:\Omega\to\mathbb Rx:Ω→R, and a filter is another such function θ\thetaθ. The group acts on signals by the inverse action on their arguments:

(ρ(g)x)(u)=x(g−1⋅u).(\rho(g)x)(u)=x(g^{-1}\cdot u).(ρ(g)x)(u)=x(g−1⋅u).

This convention makes ρ\rhoρ a left group representation on functions. Let μ\muμ be a measure on Ω\OmegaΩ invariant under the action of every element of GGG. The book states this measure convention beside its pairing formula on p. 41. The pairing and group convolution are

⟨x,θ⟩μ=∫Ωx(u)θ(u) dμ(u),(x⋆θ)(g)=⟨x,ρ(g)θ⟩μ=∫Ωx(u)θ(g−1⋅u) dμ(u).\langle x,\theta\rangle_\mu=\int_\Omega x(u)\theta(u)\,d\mu(u),\qquad (x\star\theta)(g)=\langle x,\rho(g)\theta\rangle_\mu =\int_\Omega x(u)\theta(g^{-1}\cdot u)\,d\mu(u).⟨x,θ⟩μ​=∫Ω​x(u)θ(u)dμ(u),(x⋆θ)(g)=⟨x,ρ(g)θ⟩μ​=∫Ω​x(u)θ(g−1⋅u)dμ(u).

The convolution is indexed by g∈Gg\in Gg∈G, so it is a signal on GGG, even when Ω\OmegaΩ and GGG are different spaces. Signals y:G→Ry:G\to\mathbb Ry:G→R use the regular action (ρG(h)y)(g)=y(h−1g)(\rho_G(h)y)(g)=y(h^{-1}g)(ρG​(h)y)(g)=y(h−1g). On the cyclic grid Zn\mathbb Z_nZn​, the source uses u⋅v=v−uu\cdot v=v-uu⋅v=v−u for the action of a shift uuu on an index vvv. These conventions are the ones used throughout this mission. Equation (14) and the surrounding definitions, §4.3, pp. 41–43.

Formalization targets

Group convolution is equivariant

For every h,g∈Gh,g\in Gh,g∈G and scalar signals x,θx,\thetax,θ on Ω\OmegaΩ, the main target is

((ρ(h)x)⋆θ)(g)=(ρG(h)(x⋆θ))(g)=(x⋆θ)(h−1g).((\rho(h)x)\star\theta)(g) = (\rho_G(h)(x\star\theta))(g) = (x\star\theta)(h^{-1}g).((ρ(h)x)⋆θ)(g)=(ρG​(h)(x⋆θ))(g)=(x⋆θ)(h−1g).

The theorem keeps the domain action ρ\rhoρ and the output regular action ρG\rho_GρG​ distinct. The invariant measure and transitive action are part of the source's setting. §4.3, equation (14) and the following displayed identity, p. 41; homogeneous-domain assumption, p. 43.

Source claims that support the target

The milestone list records three claims from the same section. First, the pairing matches a transformed filter to the inversely transformed signal: ⟨x,ρ(g)θ⟩μ=⟨ρ(g−1)x,θ⟩μ\langle x,\rho(g)\theta\rangle_\mu=\langle\rho(g^{-1})x,\theta\rangle_\mu⟨x,ρ(g)θ⟩μ​=⟨ρ(g−1)x,θ⟩μ​. Second, the signal action satisfies ρ(h−1)ρ(g)=ρ(h−1g)\rho(h^{-1})\rho(g)=\rho(h^{-1}g)ρ(h−1)ρ(g)=ρ(h−1g). Third, for n>0n>0n>0 on the cyclic grid, the finite-sum instance of group convolution has the form (x⋆θ)u=∑v=0n−1xvθv+u(modn)(x\star\theta)_u=\sum_{v=0}^{n-1}x_v\theta_{v+u\pmod n}(x⋆θ)u​=∑v=0n−1​xv​θv+u(modn)​. The source's side-note calls the last expression cross-correlation. §4.3, pp. 41–42.

Significance

The equality specifies what happens to every output coordinate after a group transformation of the input. Its output is a function on GGG, so the statement also fixes which action later layers must use. In the sphere example, the first convolution produces a function on the rotation group rather than a function on the sphere; the book then describes applying a second group convolution on that output. §4.3, pp. 42–43.

The result is proved in the source. The remaining work here is to make the invariant measure, the two actions, and the real integral into separately inspectable Lean definitions and to supply machine-checked proofs of the open theorem statements. The cyclic example checks the sign convention at a concrete boundary: using v−uv-uv−u for the group action yields v+uv+uv+u after applying the inverse shift. Those definitions can also support later formalizations of group-indexed layers. This mission does not assert results for learned networks or approximation power; its target is the mathematical convolution identity displayed in the book.

Difficulty

The two occurrences of ρ\rhoρ in the printed identity act on different function spaces. On the left, ρ(h)\rho(h)ρ(h) transforms a signal on Ω\OmegaΩ; on the right, the regular action transforms a function on GGG. Treating both as a single action obscures the type and can silently reverse the group multiplication order. The group need not be commutative, so this order matters. The measure must also be invariant: a Dirac measure concentrated at a point that moves under the group generally changes the pairing and breaks the claimed equivariance. In the cyclic example, an inverse shift changes the sign again, which is why the output has v+uv+uv+u rather than v−uv-uv−u.

Formalization scope

Lean represents a signal as a function Ω→R\Omega\to\mathbb RΩ→R, the group action using MulAction, and the measure as a measure on Ω\OmegaΩ. The action on signals, the pairing, group convolution, and the output regular action are explicit functions. The integral theorems require a transitive action, as the section specifies on p. 43, plus measurable spaces on GGG and Ω\OmegaΩ, a measurable group action, and an invariant measure. These are the conditions under which the source's change of variables is meaningful. The cyclic example applies the same group convolution to the counting measure on ZMod n, n>0n>0n>0, with the shift group acting by v↦v−uv\mapsto v-uv↦v−u. It does not identify a cyclic convolution with a planar convolution or assume the group and domain coincide in the general theorem.

The source describes X(Ω)\mathcal X(\Omega)X(Ω) as a Hilbert space. The Lean theorem states the integral identity for arbitrary real functions; on integrable products the pairing has its ordinary meaning, while Lean assigns zero to a nonintegrable integral. The identity remains valid at those totalized inputs because the same measure-preserving transformation relates the two integrands. No integrability hypothesis is used to reduce the stated range. The zero measure is included, but the theorem is universal over invariant measures, including nonzero counting measure on finite group actions; it cannot be proved by choosing a zero measure or an empty domain. Reusable contributions include properties of the signal action, invariant integration under actions, and finite cyclic examples. The transform-and-convolve equation (32) and the second-layer composition on GGG are outside this chunk's milestone list.

Selected references

  • M. M. Bronstein, J. Bruna, T. Cohen and P. Veličković, Geometric Deep Learning: Grids, Groups, Graphs, Geodesics, and Gauges, arXiv preprint arXiv:2104.13478v2, 2021. arXiv.
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Functional AnalysisPartial Differential EquationsSymplectic Geometry·Captain: Mazecto

Lectures on Symplectic Field Theory VI: Elliptic Regularity and Compactness of Pseudoholomorphic MapsTextbook

Motivation

A pseudoholomorphic map from a planar domain U⊆CU\subseteq\mathbb{C}U⊆C into an almost complex manifold solves the nonlinear Cauchy–Riemann equation

∂ˉJu=∂su+J(u) ∂tu=0,z=s+it.\bar\partial_Ju=\partial_su+J(u)\,\partial_tu=0,\qquad z=s+it.∂ˉJ​u=∂s​u+J(u)∂t​u=0,z=s+it.

These maps are the basic objects of Gromov's theory of holomorphic curves, of Floer homology and of symplectic field theory. Two analytic facts about them are used everywhere: solutions of low regularity are automatically smooth, and families with a uniform bound on the first derivative are precompact in Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​. A third fact, unique continuation, says that a solution is determined near a point by its derivatives there.

This mission formalizes these results locally, for maps from discs into a finite-dimensional real vector space with an almost complex structure defined on an open subset, following C. Wendl, Lectures on Symplectic Field Theory, Lecture 2 (§ 2.4–2.5) and Proposition 9.1. Mathlib has no Sobolev spaces of weakly differentiable maps, no almost complex structures and no pseudoholomorphic maps. The definitions build on the Wk,pW^{k,p}Wk,p norm of the DbarRegularity mission.

Setting

  • Target. EEE is a finite-dimensional real vector space and O⊆EO\subseteq EO⊆E is open. A smooth almost complex structure on OOO is a C∞C^\inftyC∞ map J:O→End⁡R(E)J:O\to\operatorname{End}_{\mathbb{R}}(E)J:O→EndR​(E) with J(x)2=−IdJ(x)^2=-\mathrm{Id}J(x)2=−Id. Allowing an open subset rather than all of EEE covers, for example, symplectizations of contact-type hypersurfaces.
  • Domain. U⊆CU\subseteq\mathbb{C}U⊆C is open, usually the open unit disc DDD; ∂su\partial_su∂s​u and ∂tu\partial_tu∂t​u are the derivatives in the directions 111 and iii.
  • JJJ-holomorphic maps. uuu is JJJ-holomorphic on UUU if it is differentiable there with ∂su+J(u)∂tu=0\partial_su+J(u)\partial_tu=0∂s​u+J(u)∂t​u=0.
  • Weak solutions. uuu is a Wloc1,pW^{1,p}_{\mathrm{loc}}Wloc1,p​ solution if it is continuous with values in OOO, has weak partial derivatives that lie with uuu in LpL^pLp of every compact subset of UUU, and satisfies the equation almost everywhere.
  • Convergence. Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​ convergence on an open set means uniform convergence of all derivatives on every compact subset.

Formalization targets

Goal: compactness of pseudoholomorphic discs

Let Jν→JJ_\nu\to JJν​→J in Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​ be smooth almost complex structures on OOO and let K0⊆OK_0\subseteq OK0​⊆O be compact. Every sequence of JνJ_\nuJν​-holomorphic C1C^1C1 maps uν:D→K0u_\nu:D\to K_0uν​:D→K0​ with sup⁡νsup⁡D∥Duν∥<∞\sup_\nu\sup_D\|Du_\nu\|<\inftysupν​supD​∥Duν​∥<∞ has a subsequence converging in Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​ on DDD to a smooth JJJ-holomorphic map D→K0D\to K_0D→K0​ (Wendl, Proposition 9.1).

Milestones

  1. Regularity of weak solutions. For p>2p>2p>2, a continuous Wloc1,pW^{1,p}_{\mathrm{loc}}Wloc1,p​ solution of ∂su+J(u)∂tu=0\partial_su+J(u)\partial_tu=0∂s​u+J(u)∂t​u=0 on an open UUU is C∞C^\inftyC∞ on UUU (Theorem 2.22 (1)).
  2. Uniform interior bounds. For p>2p>2p>2, smooth JνJ_\nuJν​-holomorphic discs with values in K0K_0K0​ and uniformly bounded W1,pW^{1,p}W1,p norm have derivatives of every order bounded on compact subsets of DDD, uniformly in ν\nuν (Theorem 2.22 (2a)).
  3. Convergence. For p>2p>2p>2, if such discs converge in W1,pW^{1,p}W1,p to a smooth map, they converge to it in Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​ (Theorem 2.22 (2b)).
  4. Weakly holomorphic functions. An L1L^1L1 function on DDD with ∂su+i∂tu=0\partial_su+i\partial_tu=0∂s​u+i∂t​u=0 in the sense of distributions agrees almost everywhere with a holomorphic function (Lemma 2.19).
  5. Local solutions with prescribed value. For 2<p<∞2<p<\infty2<p<∞ and A∈Lp(D,End⁡R(Cn))A\in L^p(D,\operatorname{End}_{\mathbb{R}}(\mathbb{C}^n))A∈Lp(D,EndR​(Cn)), the equation ∂su+i∂tu+Au=0\partial_su+i\partial_tu+Au=0∂s​u+i∂t​u+Au=0 has, on every sufficiently small disc, a continuous W1,pW^{1,p}W1,p solution with any prescribed value at 000 (Lemma 2.24).
  6. Local holomorphic factorization. A smooth solution of ∂sh+Jˉ(z)∂th+A(z)h=0\partial_sh+\bar J(z)\partial_th+A(z)h=0∂s​h+Jˉ(z)∂t​h+A(z)h=0, with Jˉ(z)\bar J(z)Jˉ(z) a smooth family of complex structures on EEE, is locally of the form h=Φfh=\Phi fh=Φf, where Φ(z):Cn→E\Phi(z):\mathbb{C}^n\to EΦ(z):Cn→E is a continuous family of real-linear bijections with Φ(z)∘i=Jˉ(z)∘Φ(z)\Phi(z)\circ i=\bar J(z)\circ\Phi(z)Φ(z)∘i=Jˉ(z)∘Φ(z) and fff is holomorphic (Theorem 2.26).
  7. Unique continuation. Two smooth JJJ-holomorphic discs whose derivatives of all orders agree at 000 coincide near 000 (Proposition 2.28).

Significance

The results. Regularity and Cloc∞C^\infty_{\mathrm{loc}}Cloc∞​ compactness are the local half of Gromov compactness: once a moduli space of holomorphic curves has a uniform C1C^1C1 bound, it is precompact in the smooth topology. Unique continuation is the local input for the structure theory of holomorphic curves, such as the decomposition of a curve into a simple curve and a branched cover.

Formalizing them. The mission introduces almost complex structures, pseudoholomorphic maps, weak derivatives and Wloc1,pW^{1,p}_{\mathrm{loc}}Wloc1,p​ solutions of a nonlinear first-order system, in a form that applies to any finite-dimensional target and to structures defined on an open subset. These are foundations for finite-energy holomorphic curves in symplectizations, the next stage of this series. Milestones 4 and 5 are statements about linear first-order elliptic equations in the plane, and milestone 6 is a normal form for real-linear Cauchy–Riemann equations; all three are of independent use in complex analysis.

Difficulty

The equation is nonlinear in uuu and the structures JνJ_\nuJν​ vary with ν\nuν; the statements about sequences are uniform in ν\nuν, with all constants chosen before the index. The weak formulation involves maps that are not assumed differentiable, and the conclusion of milestone 1 is classical smoothness of the given continuous map, not of a representative. The almost complex structure is only defined on an open subset of the target, so every statement keeps track of where the maps take their values. In milestone 6 the complex structure on the target varies with the point of the domain.

Formalization scope

  • Namespace JHolomorphic. The definition module JHolomorphic_Setting defines IsAlmostComplexOn, dbarJ, IsJHolomorphicOn, HasWeakPartialsOn, IsWeakJHolomorphicOn and TendstoCInftyLocOn. It imports the DbarRegularity setting for sobolevNorm (the Wk,p(U)W^{k,p}(U)Wk,p(U) norm ∑j≤k∥Djφ∥Lp(U)\sum_{j\le k}\|D^j\varphi\|_{L^p(U)}∑j≤k​∥Djφ∥Lp(U)​).
  • Spaces. EEE is a real normed space with [FiniteDimensional ℝ E], without an inner product. Cn\mathbb{C}^nCn is EuclideanSpace ℂ (Fin n). Almost complex structures have type E → E →L[ℝ] E.
  • Exponents. ppp is a real number with p>2p>2p>2, used as ENNReal.ofReal p.
  • Smoothness. Smoothness is ContDiffOn ℝ ∞ (C∞C^\inftyC∞, not analytic); derivatives of order mmm are iteratedFDeriv ℝ m.
  • Generality. Wendl states the nonlinear results for E=CnE=\mathbb{C}^nE=Cn with the normalization J(0)=iJ(0)=iJ(0)=i, u(0)=0u(0)=0u(0)=0; the statements here drop the normalization, allow an open domain of definition OOO for JJJ, and require images in a fixed compact subset of OOO in the statements about sequences.

Contributions welcome: general lemmas on weak derivatives and on LpL^pLp spaces over planar domains.

Selected references

  • C. Wendl, Lectures on Symplectic Field Theory, arXiv:1612.01009, Lecture 2 and Lecture 9. https://arxiv.org/abs/1612.01009
  • D. McDuff, D. Salamon, J-holomorphic Curves and Symplectic Topology, 2nd ed., AMS Colloquium Publications 52 (2012), Chapter 2 and Appendix B.
  • C. Abbas, H. Hofer, Holomorphic Curves and Global Questions in Contact Geometry, Birkhäuser (2019).
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Quantum Information·Captain: Goku

Implementation of group-covariant POVMs by orthogonal measurementsResearch Paper

Motivation

We consider group-covariant positive operator valued measures (POVMs) on a finite dimensional quantum system. Following Neumark's theorem a POVM can be implemented by an orthogonal measurement on a larger system. Accordingly, our goal is to find an implementation of a given group-covariant POVM by a quantum circuit using its symmetry. Based on representation theory of the symmetry group we develop a general approach for the implementation of group-covariant POVMs which consist of rank-one operators. The construction relies on a method to decompose matrices that intertwine two representations of a finite group. We give several examples for which the resulting quantum circuits are efficient. In particular, we obtain efficient quantum circuits for a class of POVMs generated by Weyl-Heisenberg groups. These circuits allow to implement an approximative simultaneous measurement of the position and crystal momentum of a particle moving on a cyclic chain.

This mission is the statement-level formalization of Implementation of group-covariant POVMs by orthogonal measurements (arXiv:quant-ph/0407054v1). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

13 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Symmetry-preserving orthogonal dilation (Paper main result: symmetry-preserving orthogonal dilation, PDF p. 2). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Selected references

  • Implementation of group-covariant POVMs by orthogonal measurements, arXiv:quant-ph/0407054v1, https://arxiv.org/abs/quant-ph/0407054v1
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Quantum Information·Captain: Goku

Entropic Fluctuations in Statistical Mechanics I. Classical Dynamical SystemsResearch Paper

Motivation

Within the abstract framework of dynamical system theory we describe a general approach to the Transient (or Evans-Searles) and Steady State (or Gallavotti-Cohen) Fluctuation Theorems of non-equilibrium statistical mechanics. Our main objective is to display the minimal, model independent mathematical structure at work behind fluctuation theorems. Besides its conceptual simplicity, another advantage of our approach is its natural extension to quantum statistical mechanics which will be presented in a companion paper. We shall discuss several examples including thermostated systems, open Hamiltonian systems, chaotic homeomorphisms of compact metric spaces and Anosov diffeomorphisms.

This mission is the statement-level formalization of Entropic Fluctuations in Statistical Mechanics I. Classical Dynamical Systems (arXiv:1009.3248v2). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

21 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Finite-time Evans–Searles theorem (Proposition 3.3, PDF p. 10). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

79 results of the paper are not stated yet, because the library lacks an interface they need:

  • Proposition 3.9: weightedTransferOperators / actual closed Liouvillean / resolvent (hard)
  • Proposition 4.2: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 4.3: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 4.5: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 4.6: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 5.6: Unpinned/incorrect source hypothesis or conclusion for Proposition 5.6 (source-ambiguity)
  • Proposition 5.15: Unpinned/incorrect source hypothesis or conclusion for Proposition 5.15 (source-ambiguity)
  • Proposition 5.16: weightedTransferOperators / actual closed Liouvillean / resolvent (hard)
  • Proposition 5.17: Unpinned/incorrect source hypothesis or conclusion for Proposition 5.17 (source-ambiguity)
  • Proposition 6.3: Unpinned/incorrect source hypothesis or conclusion for Proposition 6.3 (source-ambiguity)
  • Proposition 6.4: Unpinned/incorrect source hypothesis or conclusion for Proposition 6.4 (source-ambiguity)
  • Proposition 6.5: weightedTransferOperators / actual closed Liouvillean / resolvent (hard)
  • Proposition 9.1: Gaussian cylinder probability, trace-class quadratic observable and evolved covariance (hard)
  • Proposition 9.2: Gaussian cylinder probability, trace-class quadratic observable and evolved covariance (hard)
  • Proposition 9.3: Unpinned/incorrect source hypothesis or conclusion for Proposition 9.3 (source-ambiguity)
  • Theorem 9.4: Unpinned/incorrect source hypothesis or conclusion for Theorem 9.4 (source-ambiguity)
  • Proposition 9.5: Unpinned/incorrect source hypothesis or conclusion for Proposition 9.5 (source-ambiguity)
  • Corollary 10.4: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 10.5: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Corollary 10.6: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 10.7: Unpinned/incorrect source hypothesis or conclusion for Proposition 10.7 (source-ambiguity)
  • Proposition 10.9: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 10.11: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 10.12: Resolution of printed sup versus inf in the concave rate, and the actual source weak-Gibbs/pressure interface (source-ambiguity)
  • Proposition 10.13: Resolution of printed sup versus inf in the concave rate, and the actual source weak-Gibbs/pressure interface (source-ambiguity)
  • Proposition 10.14: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 10.15: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Corollary 10.16: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Proposition 11.2: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • Proposition 11.4: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • Proposition 11.5: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • Theorem 11.6: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • discrete-integrated-entropy: Well-defined separate extended expectations of every transported discrete summand (source-ambiguity)
  • reference-L2-moment-representation: weightedTransferOperators / actual closed Liouvillean / resolvent (hard)
  • discrete-transfer-representation: Unpinned/incorrect source hypothesis or conclusion for discrete-transfer-representation (source-ambiguity)
  • differentiable-jacobian-entropy: Euclidean C1 dynamics on a compact invariant set, normalized restricted Lebesgue probability, and its RN/Jacobian and divergence identification (hard)
  • thermostat-energy-and-entropy: Unpinned/incorrect source hypothesis or conclusion for thermostat-energy-and-entropy (source-ambiguity)
  • gas-exact-trajectory: Unpinned/incorrect source hypothesis or conclusion for gas-exact-trajectory (source-ambiguity)
  • gas-finite-pressure: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • canonical-smooth-flux: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • ges-functional-structure: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • finite-response-positivity: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • finite-einstein-relations: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • hamiltonian-flux-and-cocycle: General finite-dimensional coupled Hamiltonian system, normalized Gibbs probability on its convergence domain, and Poisson-bracket reservoir fluxes (hard)
  • hamiltonian-TRI-criterion: Unpinned/incorrect source hypothesis or conclusion for hamiltonian-TRI-criterion (source-ambiguity)
  • harmonic-finite-gaussian-formula: Unpinned/incorrect source hypothesis or conclusion for harmonic-finite-gaussian-formula (source-ambiguity)
  • gas-asymptotic-entropy: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • gas-asymptotic-pressure-and-response: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • finite-harmonic-zero-currents: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-thermodynamic-limit: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-scattering-pressure: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-explicit-pressure-and-current: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-explicit-LDP: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-analytic-bound-and-FDT: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • harmonic-energy-conservation: Unpinned/incorrect source hypothesis or conclusion for harmonic-energy-conservation (source-ambiguity)
  • gas-NESS-and-GC-failure: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • harmonic-NESS-and-GGC: concrete pinned-chain operators, Gaussian configuration laws and Fredholm/scattering calculus (hard)
  • regular-fluctuation-implications: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • bernoulli-pressure-and-NESS: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • bernoulli-FDT: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • baker-Bernoulli-isomorphism: Unpinned/incorrect source hypothesis or conclusion for baker-Bernoulli-isomorphism (source-ambiguity)
  • dilation-pressure-and-NESS: actual microcanonical/Bernoulli/dilation model and its flow-induced laws (hard)
  • dilation-linear-response-counterexamples: Unpinned/incorrect source hypothesis or conclusion for dilation-linear-response-counterexamples (source-ambiguity)
  • gaussian-configuration-and-support: Gaussian cylinder probability, trace-class quadratic observable and evolved covariance (hard)
  • pressure-time-reversal: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • RN-entropy-homology: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • positive-Markov-fluctuations: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Markov-controlled-FDT: source pressure, partition entropy, normalized weak-Gibbs class and regular/specification dynamics (hard)
  • Anosov-Jacobian-reversal-homology: Unpinned/incorrect source hypothesis or conclusion for Anosov-Jacobian-reversal-homology (source-ambiguity)
  • Anosov-finite-time-ES: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • Anosov-unique-NESS-and-LDP: Ck-Anosov manifold, stable/unstable Jacobians and SRB/NESS parameter family (hard)
  • Proposition 5.15 part-2: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 5.15 parts-3-4: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • Proposition 6.4 part-2: actual force-dependent flux laws, mixed moment regularity and full fluctuation-dissipation property (hard)
  • NESS-L2-moment-representation: weightedTransferOperators / actual closed Liouvillean / resolvent (hard)
  • regular-pressure-limit-exchange: Unpinned/incorrect source hypothesis or conclusion for regular-pressure-limit-exchange (source-ambiguity)
  • gaussian-parameter-extension: Unpinned/incorrect source hypothesis or conclusion for gaussian-parameter-extension (source-ambiguity)
  • Smale-transitivity-specification: Unpinned/incorrect source hypothesis or conclusion for Smale-transitivity-specification (source-ambiguity)
  • Anosov-flow-extensions: Unpinned/incorrect source hypothesis or conclusion for Anosov-flow-extensions (source-ambiguity)

Selected references

  • Entropic Fluctuations in Statistical Mechanics I. Classical Dynamical Systems, arXiv:1009.3248v2, https://arxiv.org/abs/1009.3248v2
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A general proof of Landauer-Büttiker formulaResearch Paper

Motivation

We point out a general argument leading from the formula for currents through an open mesoscopic system given by the theory of non-equilibrium steady states (NESS) to the Landauer-Büttiker formula.

This mission is the statement-level formalization of A general proof of Landauer-Büttiker formula (arXiv:math-ph/0603030v4). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

1 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Two-channel optical theorem with the Landauer–Büttiker transition normalization (Equations (15)–(17), PDF p. 5). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

6 results of the paper are not stated yet, because the library lacks an interface they need:

  • Equation (19), main result; assumptions pp.2–4 and proof pp.5–6: Precisely specified rigged-Hilbert-space stationary scattering data, admissible resolvent boundary values, and a justified trace-to-transmission integral interface for the actual model. (source-ambiguity)
  • Remark i, equation (24): The stationary scattering interface of (19), plus an energy-current commutator with its actual operator domain, trace-class extension and energy-weighted integrability. (source-ambiguity)
  • Remark ii, unequal reservoir spectra: The stationary scattering interface of (19), with measurable channel fibers indexed by the distinct reservoir spectral supports. (source-ambiguity)
  • Remark iii, equation (25): The stationary scattering interface of (19) for finitely many actual reservoirs, tied to the same incoming occupation and on-shell transition matrix. (source-ambiguity)
  • Remark iii, charge conservation and normality: An assembled unbounded self-adjoint reservoir/sample model and canonical incoming occupation and finite-rank charge-current trace, together with the same model’s on-shell scattering representation. (hard)
  • Remark iv, multiple spectral channels: Measurable reservoir channel fields of unrestricted multiplicity, correctly directed transmission blocks and their trace-class products, attached to the actual trace-current model. (source-ambiguity)

Selected references

  • A general proof of Landauer-Büttiker formula, arXiv:math-ph/0603030v4, https://arxiv.org/abs/math-ph/0603030v4
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Cellularity and the Jones basic constructionResearch Paper

Motivation

We establish a framework for cellularity of algebras related to the Jones basic construction. Our framework allows a uniform proof of cellularity of Brauer algebras, ordinary and cyclotomic BMW algebras, walled Brauer algebras, partition algebras, and others. Our cellular bases are labeled by paths on certain branching diagrams rather than by tangles. Moreover, for the class of algebras that we study, we show that the cellular structures are compatible with restriction and induction of modules. Applied to cyclotomic BMW algebras, our method allows a new a shorter proof of the finite spanning result and isomorphism with cyclotomic Kauffman tangle algebras.

This mission is the statement-level formalization of Cellularity and the Jones basic construction (arXiv:0906.1496v2). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

3 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Free modules embed into their fraction-field scalar extension (Lemma 2.20, PDF p. 15). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

70 results of the paper are not stated yet, because the library lacks an interface they need:

  • Lemma 2.1: Tagged involution twist of both bimodules and their balanced tensor; descended C-B actions; canonical twist-reversing tensor map (hard)
  • Lemma 2.9: Invariant two-sided ideals, split-ideal predicate with actual left ideal, and M tensor_R i(M) with both A actions and swap involution (hard)
  • Lemma 2.10: Finite proper cell chains with split successive quotient ideals, actual quotient involutions, and relaxed cellular data (hard)
  • Proposition 2.13: Lambda-cell net on upward-closed label sets, quotient bimodule actions and fixed-label cell data (hard)
  • Lemma 2.19: Scalar-extended noncommutative algebra/module actions and canonical balanced-tensor base-change map, including optional left and right B^F actions (hard)
  • Lemma 2.22: Constructed cell modules and coherent towers; all finite induction/restriction cell filtrations; actual generic inclusion multiplicities (hard)
  • Lemma 2.23: Actual generic multiplicity-free branching paths and reindexed cellular data on the original label posets (hard)
  • Theorem 3.2: All eight framework axioms on actual towers; constructed coherent cell-data family; reflected label order and branching multiplicities; same-level ideal-action scalar extension (hard)
  • Lemma 4.1: Iterated noncommutative balanced tensor with canonical fraction-field base change and both optional B^F actions (hard)
  • Lemma 4.2: Semisimple noncommutative algebra, two-sided ideal as a bimodule, and the induced contraction map on iterated balanced tensors (hard)
  • Proposition 4.3: Full finite-tower induction setup; actual J(Gamma), Jhat(Gamma), tensor domain with A_(n+1) actions, unscaled Phi and inclusion beta (hard)
  • Lemma 4.4: Canonical Phi and beta for nested cellular order-ideal spans within the finite-tower induction setup (hard)
  • Lemma 4.5: Canonical Phi from the actual free tensor domain to Jhat(Gamma), with ambient bimodule actions (hard)
  • Corollary 4.6: Canonical unscaled map xe_n tensor e_ny to xe_ny between actual A_(n+1) bimodules (hard)
  • Proposition 4.7: Actual Jhat cell net; ambient cellular ideal; lifted ordinal-sum cellular datum and its tensor cell modules (hard)
  • Corollary 4.8: Constructed next-level cellular datum and reflected disjoint-union label poset with both order cases (hard)
  • Corollary 4.9: Same constructed next-level cell modules and basic-construction ideal-action submodule, extended to F only in the lower-label case (hard)
  • Proposition 4.10: Restriction of every actual newly constructed cell module and genuine finite A_n-submodule filtrations (hard)
  • Lemma 4.11: Scalar-extended noncommutative semisimple algebra and the canonical map id_P tensor inclusion on balanced tensors (hard)
  • Lemma 4.12: Given actual finite cell filtration; canonical tensor embeddings, quotient maps, transported labels and next-level module action (hard)
  • Lemma 4.13: Actual restriction functor and the two balanced tensor modules with A_(n+1)-linear equivalences (hard)
  • Proposition 4.14: Ideal-tensor module, actual induction module, canonical embedding and quotient, and both Q_(n+1) and A_(n+1) cell filtrations (hard)
  • Corollary 4.15: Simultaneously constructed cellular data and induction/restriction cell filtrations through level n+1 (hard)
  • Corollary 4.16: Actual generic simple modules and inclusion matrices through n+1, and reflection preserving edge multiplicities (hard)
  • Lemma 5.2: Brauer loop-count diagram algebra, inclusions and contraction e_n; actual corner and right-product submodules (hard)
  • Lemma 5.3: Canonical Brauer strand inclusion, e_n, right-ideal images and multiplication-by-e_n map (hard)
  • Proposition 5.4: Concrete generic Brauer and symmetric-group towers, involutions and all-eight-axiom framework predicate (hard)
  • Corollary 5.5: Actual specialized Brauer cellular tower, parity Young labels, up-down paths, and whole compatible datum family (hard)
  • Proposition 5.6: Temperley-Lieb presented algebra and structure maps over Z[delta]; constant quotient tower; all framework axioms (hard)
  • Corollary 5.7: Specialized Temperley-Lieb cellular tower with actual at-most-two-row Young labels and standard-tableau bases (hard)
  • Lemma 5.9: Ordinary BMW presentation with all seven relation groups, canonical strand maps, and corner/right-product submodules (hard)
  • Lemma 5.10: Ordinary BMW algebra and generator-preserving homomorphism between levels, right-ideal images, and multiplication map (hard)
  • Proposition 5.11: Generic BMW coefficient quotient ring, ordinary BMW/Hecke towers with matching quadratic convention, all framework axioms (hard)
  • Corollary 5.12: Full BMW coefficient systems and actual specialized coherent cell data with parity Young labels and up-down bases (hard)
  • Lemma 5.20: Geometric cyclotomic KT_0 with all local affine-loop/skein relations, canonical empty diagram, and actual W_0 (hard)
  • Lemma 5.21: Actual admissible cyclotomic BMW/KT algebras and canonical phi and strand homomorphisms (hard)
  • Lemma 5.23: Full generic admissible coefficient system and presented cyclotomic W_n; actual cardinal module rank and pairing count (hard)
  • Lemma 5.24: Actual generic cyclotomic W_n and geometric KT_n, canonical phi and finite spanning-set cardinality (hard)
  • Lemma 5.25: Actual W_0,W_1,W_2,KT_1 and cyclotomic H_1; canonical maps and finite free rank (hard)
  • Lemma 5.26: Canonical cyclotomic phi maps at all levels through n, geometric KT and BMW strand maps, and corner/right-ideal images (hard)
  • Theorem 5.27: Concrete generic cyclotomic BMW/Hecke framework pair, geometric KT with canonical phi, inclusions and constructed coherent cell data (hard)
  • Corollary 5.28: Admissible specialized cyclotomic BMW/KT towers, canonical phi, multipartition cellular modules and up-down bases (hard)
  • Lemma 5.31: Actual walled Brauer diagram subalgebras, long-range e_(a,b), both strand inclusions and both closure maps (hard)
  • Lemma 5.32: Walled Brauer two-sided contraction ideal and actual involutive quotient to the product symmetric-group algebra (hard)
  • Lemma 5.33: Walled Brauer left/right strand inclusions and contraction right-ideal images in two different ambient algebras (hard)
  • Lemma 5.34: Actual Brauer and walled diagram multiplication and normalized full-closure traces over Q(delta) (hard)
  • Lemma 5.35: Walled Brauer algebra over Q(delta) and finite product-of-full-matrix-algebras meaning of split semisimplicity (hard)
  • Proposition 5.36: Alternating walled algebra and quotient towers, generators f_n, and generalized framework with replacement axiom (3 prime) (hard)
  • Corollary 5.38: Walled cellular data for all pairs, both restriction/induction filtrations, integer size-difference labels and augmented branching paths (hard)
  • Lemma 5.39: Actual even/odd partition diagram algebras and propagating ideals, quotient involutions and symmetric-group algebras (hard)
  • Lemma 5.40: Partition diagram products, embeddings, propagating ideal J_k and image of A_(k-1)p_(k-1)A_(k-1) (hard)
  • Lemma 5.41: Partition generators p_k, canonical level inclusions, and corner/right-product submodules with alternating parity (hard)
  • Lemma 5.42: Partition tower canonical inclusions and actual map x to x p_(k-1), correcting the printed e notation (hard)
  • Lemma 5.43: Actual partition diagram algebra and its alternating normalized closure trace over Q(delta) (hard)
  • Proposition 5.45: Concrete generic partition and repeated symmetric-group quotient towers, p generators, and all framework axioms (hard)
  • Corollary 5.46: Actual specialized partition cellular tower, corrected half-level Young labels and Lemma 5.44 branching-path bases (hard)
  • Lemma 5.47: Oriented A-labelled planar algebra, western-depth subalgebra and every label generator a^(k) (hard)
  • Lemma 5.48: Actual depth-restricted labelled planar algebra, strand inclusions and e generators with corner/right-product submodules (hard)
  • Lemma 5.49: Contour strand homomorphisms, right-ideal images and actual multiplication-by-e_(n-1) map (hard)
  • Lemma 5.50: Generic labelled contour algebra and normalized closure trace extended from the specified cellular label algebra (hard)
  • Lemma 5.51: Actual generic contour algebra and finite-dimensional split matrix-block decomposition predicate (hard)
  • Proposition 5.52: Concrete contour and tensor-power quotient towers over R_0[delta], with orientation-sensitive embeddings and all framework axioms (hard)
  • §2.2: cell modules and canonical layer tensor isomorphism: Cell representation constructed from triangular coefficients; column and layer quotient actions; invariant cell ideals; canonical bimodule tensor-layer equivalence (hard)
  • Remark 2.6: extensions of cellular algebras: Ambient cellular-ideal data, actual quotient involution and basis, ordinal-sum order and every choice of quotient-basis lifts (hard)
  • Remark 2.11: strict cell chains: Finite proper cell chains with involution-invariant R-module complements at every successive pair (hard)
  • Remark 2.14: strict cell nets: Fixed-Lambda cell nets, all nested-ideal and principal-layer invariant complements, and strict cellular data (hard)
  • Remark 2.24: inductively lifted path bases: Actual restriction filtrations and quotient isomorphisms, recursive arbitrary R-linear lifts, and actual branching paths (hard)
  • Remark 3.3: path-indexed cell bases: Constructed basic-construction cell data on reflected label posets and multiplicity-free generic branching paths (hard)
  • Remark 5.29: strictly cellular cyclotomic Murphy-type bases: Full generic cyclotomic BMW presentation and coefficient system, strict cellular data and multipartition up-down path bases (hard)
  • Remark 5.37: quotient walled branching diagram: Product symmetric-group quotient tower, its actual generic simple modules and inclusion multiplicities, and bipartition Young labels (hard)

Selected references

  • Cellularity and the Jones basic construction, arXiv:0906.1496v2, https://arxiv.org/abs/0906.1496v2
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A Cocycle Model for Topological and Lie Group CohomologyResearch Paper

Motivation

We propose a unified framework in which the different constructions of cohomology groups for topological and Lie groups can all be treated on equal footings. In particular, we show that the cohomology of "locally continuous" cochains (respectively "locally smooth" in the case of Lie groups) fits into this framework, which provides an easily accessible cocycle model for topological and Lie group cohomology. We illustrate the use of this unified framework and the relation between the different models in various applications. This includes the construction of cohomology classes characterizing the string group and a direct connection to Lie algebra cohomology.

This mission is the statement-level formalization of A Cocycle Model for Topological and Lie Group Cohomology (arXiv:1110.3304v3). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

2 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Theorem VI.2: delta-functor comparison principle (Theorem VI.2: delta-functor comparison principle, PDF p. 25). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

63 results of the paper are not stated yet, because the library lacks an interface they need:

  • Theorem IV.5 (Comparison Theorem); introductory theorem p. 2: Segal-Mitchison and global continuous cohomology as concrete delta-functors on locally contractible k-G-modules (hard)
  • Remark I.2: local coefficient long exact sequences: Unnormalized continuous/smooth local cohomology and lift-defined connecting homomorphisms (hard)
  • Remark I.3: degrees zero, one, two: Low-degree regular cohomology and the Baer group of locally trivial abelian extensions (hard)
  • Remark I.4: comparison in low degrees and global coefficient sequence: Actual global-to-local cohomology maps, globally split coefficient sequences and connected-G extension comparison (hard)
  • Proposition I.5: loop-contractible comparison (cited): Loop-contractible comparison for unnormalized regular cochain complexes (hard)
  • Lemma I.6: discrete smooth-continuous comparison: Inclusion-induced map on the unnormalized discrete-coefficient local smooth and local continuous cohomologies (hard)
  • Proposition I.7: finite-dimensional comparison: Regular cohomology inclusion for quasi-complete locally convex discrete-submodule quotients (hard)
  • Remark I.8: ordinary-product variant: Ordinary-product local/global cohomology and locally split connecting sequences (hard)
  • Remark II.2: simplicial sheaves form an abelian category with injectives: Category of compatible abelian sheaves on a simplicial space, with componentwise operations (hard)
  • Lemma II.4: left exact section functor: The actual simplicial section functor ker(D0-D1) (hard)
  • Proposition II.6: simplicial sheaf spectral sequence: Derived simplicial section cohomology, first-quadrant spectral sequence and convergence filtration (hard)
  • Corollary II.8: acyclic component calculation: Cosimplicial section Moore complex and its comparison with derived simplicial sections (hard)
  • Lemma II.11: simplicial coefficient sequences: Continuous and smooth simplicial coefficient functors with natural connecting maps (hard)
  • Proposition II.12: contractible simplicial coefficients: Contractible-coefficient simplicial-to-global comparison (hard)
  • Proposition II.15: local sheaves are soft: Local-regularity abelian sheaf, softness and positive-degree sheaf cohomology (hard)
  • Corollary II.16: local sheaf model: Derived sections of local-regularity simplicial sheaves and local cohomology (hard)
  • Remark II.17: sheaf-to-local comparison morphisms: Sheaf-inclusion-induced natural morphisms from simplicial to local cohomology (hard)
  • Remark III.2: construction of semi-simplicial good covers: Coherent semi-simplicial open covers and good refinements (hard)
  • Proposition III.4: Cech sequences and spectral sequence: Leray comparison for arbitrary sheaves on a fixed good cover (source-ambiguity)
  • Remark III.5: explicit degree-two comparison: Consistent explicit right-fiber-coordinate Cech comparison (source-ambiguity)
  • Lemma IV.3: sections of the soft embedding (cited): Thin Segal realization E_G(A), quotient B_G(A), local/global sections (hard)
  • Proposition IV.4: soft module acyclicity: Globally continuous cohomology of the actual coinduced k-function module (hard)
  • Remark IV.6: weaker loop-contractible comparison axiom: Loop contraction of actual Segal realization/coinduction and comparison on contractible coefficients (hard)
  • Corollary IV.7: Natural Segal-Mitchison/simplicial cohomology comparison (hard)
  • Corollary IV.8: Canonical local/Segal comparison and simplicial-to-local inclusion map (hard)
  • Corollary IV.9: All three canonical arrows between smooth and continuous simplicial/local cohomology (hard)
  • Corollary IV.10: Segal cohomology and fixed-good-cover Cech total cohomology (hard)
  • Remark IV.11: explicit Cech-to-local map: Staircase Cech-to-local comparison as a delta-functor morphism (hard)
  • Remark IV.12: Flach comparison: Precise Flach external cohomology functor and coefficient category (hard)
  • Remark IV.12: smooth infinity-groupoid comparison: The cited big smooth topos cohomology and exact Schreiber comparison (hard)
  • Remark IV.13: Moore and locally continuous measurable comparisons: Polish coefficient category, Borel/local-measurable cochain quotients and delta-functor comparisons (hard)
  • Remark IV.14: bounded comparison for compact groups: Bounded and unbounded continuous Banach-coefficient cohomology with inclusion-induced map (hard)
  • Remark IV.16(1): Twisted classifying-space cohomology with pi0 action and Hurewicz comparison (hard)
  • Remark IV.16(2): Contractible-G global/local/Segal comparison maps (hard)
  • Remark IV.16(3): Discrete-submodule quotient coefficients, twisted BG cohomology and degree-shift comparison (hard)
  • Example V.1(1): spherical string four-cocycle: Actual smooth simplex fillings and their homology-valued four-cocycle (hard)
  • Example V.1(2): integral string cocycle and connecting identity: Cartan-form singular integral, real lift, string cocycle and actual coefficient connecting map (hard)
  • Example V.1(3) and continuation: external string models: External strict and stacky string models and characteristic classes (hard)
  • Example V.2: characteristic spherical cocycles: Based simplex-valued filling choices, singular homology cocycle and choice independence (hard)
  • Example V.2: realization gives a connected cover: Correctly indexed path-loop extension and connected-cover realization (source-ambiguity)
  • Theorem V.4: crossed-module classification: Topologically split crossed modules, zigzag equivalence and characteristic 3-class (hard)
  • Remark V.5: metrizable crossed-module realization: The constructed metrizable crossed module and string-generator specialization (hard)
  • Remark V.6: topology on local cohomology: Shrinking-neighborhood colimit topology on local cochains and quotient cohomology (hard)
  • Remark V.7: cup products and compatibility: Actual kTop tensor cup product, induced cohomology product and differentiation compatibility (hard)
  • Equation (13): degree-two topological characteristic sequence: Bundle-characteristic map on actual ordinary-product H^2 and its compatible-extension image (hard)
  • Proposition V.8: explicit Cech characteristic map: Explicit translated-cover Cech cocycle and induced natural characteristic homomorphism (hard)
  • Proposition V.9: edge map is the explicit characteristic map: Filtered simplicial spectral-sequence edge and its actual characteristic-map square (hard)
  • Remark V.10: degree-one edge with trivial action: Degree-one trivial-action edge and characteristic map (hard)
  • Remark V.11: other edge is inclusion of global cochains: Other filtered edge, E2^(n,0) identification and inclusion-induced global-to-local map (hard)
  • Corollary V.12: injectivity of the characteristic map: Actual tau_(n+1) on discrete-coefficient local cohomology and full Cech cohomology (hard)
  • Remark V.13: primitive image: Cech pullbacks along multiplication/projections and the range of actual tau (hard)
  • Remark V.13: string classes are generators: Integral string classes, characteristic isomorphisms and generator property (hard)
  • Remark V.14: kernel of differentiation: Differentiation of actual local smooth quotient cohomology (hard)
  • Remark V.14: discrete-coefficient exact sequence: Continuity of the same coefficient action after discretizing A (source-ambiguity)
  • Remark V.14: van Est comparison (cited): Actual differentiation map, van Est comparison and split de Rham extension (hard)
  • Remark V.14: period criterion and explicit integration: Consistent equivariant simplex integral and spherical period map for nontrivial coefficients (source-ambiguity)
  • Example VI.5: effacement for sheaf cohomology: Positive-degree Cech/sheaf cohomology of actual E_G(A) (hard)
  • Remark VI.6: counterexample to weaker comparison hypotheses: Concrete geometric counterexamples to weakened effacement hypotheses (hard)
  • Section VII observation 1: invariants of a coinduced module: Coinduced k-function module and invariants on admissible extensions (hard)
  • Section VII observation 2: soft resolutions compute SM: Arbitrary soft resolution, constituent local sections and its invariant cohomology complex (hard)
  • Section VII observation 3: contractible coinduced quotients: Contractible coinduced quotient and its canonical coinduction isomorphism (hard)
  • Section VII conclusion: SM soft acyclicity: Exact invariant augmented soft resolution and positive-degree Segal cohomology (hard)
  • Section VII conclusion: SM equals global cohomology on contractible coefficients: Homogeneous coinduced resolution, natural invariant cohomology and global comparison (hard)

Selected references

  • A Cocycle Model for Topological and Lie Group Cohomology, arXiv:1110.3304v3, https://arxiv.org/abs/1110.3304v3
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Quantum Information·Captain: Goku

Differential Calculus, Manifolds and Lie Groups over Arbitrary Infinite FieldsResearch Paper

Motivation

We present an axiomatic approach to finite- and infinite-dimensional differential calculus over arbitrary infinite fields (and, more generally, suitable rings). The corresponding basic theory of manifolds and Lie groups is developed. Special attention is paid to the case of mappings between topological vector spaces over non-discrete topological fields, in particular ultrametric fields or the fields of real and complex numbers. In the latter case, a theory of differentiable mappings between general, not necessarily locally convex spaces is obtained, which in the locally convex case is equivalent to Keller's C^k_c-theory.

This mission is the statement-level formalization of Differential Calculus, Manifolds and Lie Groups over Arbitrary Infinite Fields (arXiv:math/0303300v1). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

17 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Regularity of a co-restriction to a subspace (Lemma 10.1, PDF p. 48). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

65 results of the paper are not stated yet, because the library lacks an interface they need:

  • Remark 1.2: C0Concept, ConceptLinearMaps (hard)
  • Remark 1.4: C0Concept, ConceptDense (hard)
  • Proposition 2.2: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, ConceptLinearMaps (hard)
  • Example 2.3: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Lemma 2.6: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Proposition 3.1 (Chain Rule): C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, TangentMapOnDomain, ExtendedTangentMap (hard)
  • 3.2 Linearity: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • 3.3 Product rule: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, ConceptBilinearMap (hard)
  • 3.4 Polynomial maps: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, ModulePolynomialMap (hard)
  • 3.5 Quotient rule: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, ConceptInverseAlgebra (hard)
  • 3.6 Rational maps: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, ModulePolynomialMap, RationalMap (hard)
  • 3.7 Direct Products: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • 3.8 Rule on partial derivatives: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, PartialDifferenceQuotient (hard)
  • Lemma 3.9: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, PartialDifferenceQuotient (hard)
  • Remark 4.2: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Example 4.3: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Lemma 4.4: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Proposition 4.5: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Lemma 4.6 (Schwarz): C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, HigherDifferential (hard)
  • Lemma 4.8: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, HigherDifferential (hard)
  • Lemma 4.9: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Theorem 5.1: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, TaylorCoefficient, TaylorRemainder (hard)
  • Lemma 5.2: C0Concept, FiniteExpansion (hard)
  • Proposition 5.3: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, TaylorCoefficient, HigherDifferential (hard)
  • Theorem 5.4: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, TaylorCoefficient, TaylorRemainder, HigherDifferential (hard)
  • Unnumbered second-quotient identity after Theorem 5.4: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, HigherDifferential, TaylorCoefficient (hard)
  • Lemma 5.5: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Theorem 5.6: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, TaylorCoefficient, TaylorRemainder, ModulePolynomialMap (hard)
  • Lemma 6.1: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, CurveDividedDifference (hard)
  • Proposition 6.2: C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential, CurveDividedDifference, HigherDifferential, TaylorCoefficient, TaylorRemainder (hard)
  • Remark 6.4: C0Concept, ConceptDense (hard)
  • Lemma 6.6: C0Concept standing environment, plus symmetric raw-quotient splicing identity (hard)
  • Lemma 6.7: SchikhofCk, CurveDividedDifference (hard)
  • Lemma 6.8: SchikhofCk, CurveDividedDifference, C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Proposition 6.9: SchikhofCk, CurveDividedDifference, C0Concept, ConceptCk, ExtendedDifferenceQuotient, Differential (hard)
  • Lemma 7.1: The Section 7 continuous C^0-concept construction over a Hausdorff commutative topological ring: the class of all Hausdorff topological K-modules, product topologies, and C^0(U,F) equal to continuous maps. Package axioms I.1–I.5 and II.1–II.5 and prove III: for every open U ⊆ K and Hausdorff topological K-module F, continuous f,g : U → F agreeing on U ∩ {a : K | IsUnit a} agree everywhere, assuming the units are dense. Include the nondiscrete topological-field specialization; open units and continuous inversion are the source’s standing topological-ring requirements. (hard)
  • Proposition 7.4: MichalBastianiCk, ExtendedDifferenceQuotient, Differential (hard)
  • Lemma 7.5: MichalBastianiCk, RepresentedWeakIntegral, FirstVariableDifferential (hard)
  • Lemma 7.6: MichalBastianiCk, RepresentedWeakIntegral, FirstVariableDifferential (hard)
  • Proposition 7.7: MichalBastianiCk, LocallyConvexComplexAnalytic, ContinuousDiagonalPolynomial, MackeyComplete, ExtendedDifferenceQuotient, Differential (hard)
  • Proposition 7.11: PolynormedSpace, StrictDifferentiable, StrictCk, ExtendedDifferenceQuotient, Differential (hard)
  • Proposition 7.20: UltrametricLocallyConvexSpace, ContinuousDiagonalPolynomial, PolynomialSeminorm, StrictConvergenceIndicatrix, UltrametricAnalytic, ExtendedDifferenceQuotient, Differential (hard)
  • §7.3 Rational calculus: C0Concept, RationalMap, ZariskiVectorTopology, ConceptCk (hard)
  • Remark 7.21: AlgebraicKGroup, RationalLieGroup (source-ambiguity)
  • §7.4 Convenient calculus: C0Concept, CInfinityRefinement, MackeyComplete, ConvenientSmoothMap, ConceptCk (hard)
  • §8.1 Category and products: ConceptManifold, ManifoldCkMap, ConceptProductManifold, SmoothScalarFunctions (hard)
  • §8.2 Tangent functor: ConceptManifold, ManifoldCkMap, TangentVector, ConceptTangentBundle, ManifoldTangentMap (hard)
  • §8.3 Bundle gluing: ConceptManifold, ManifoldCkMap, SmoothBundleCocycle, ConceptFiberBundle, ConceptVectorBundle (hard)
  • §8.4 Sections and derivations: ConceptVectorBundle, SmoothSection, VectorField, SmoothScalarFunctions, VectorFieldDerivation, ManifoldTangentMap (hard)
  • Example 8.2: VectorField, SmoothScalarFunctions, VectorFieldDerivation, QuasiBanachLp, ConceptManifold (hard)
  • Example 8.3: VectorField, VectorFieldDerivation, SmoothScalarFunctions, HigherDifferential, CompactSymmetricBilinearForms, ConceptManifold (hard)
  • Theorem 8.4: VectorField, VectorFieldBracket, ConceptManifold, ManifoldTangentMap (hard)
  • Lemma 8.5: VectorField, VectorFieldBracket, RelatedVectorFields, ManifoldTangentMap, ConceptDiffeomorphism (hard)
  • Unnumbered Lie homomorphism after Lemma 8.5: VectorField, VectorFieldBracket, VectorFieldDerivation, SmoothScalarFunctions (hard)
  • §9.1 Tangent multiplication: ManifoldWithMultiplication, ConceptTangentBundle, ManifoldTangentMap (hard)
  • §9.2 Tangent Lie group: ConceptLieGroup, ConceptTangentBundle, ManifoldTangentMap, LieGroupMorphism (hard)
  • §9.3 Left invariant fields: ConceptLieGroup, LeftInvariantVectorField, VectorFieldBracket, TangentLieAlgebra, ManifoldTangentMap (hard)
  • Theorem 9.1 (paper seed: Lie functor): ConceptLieGroup, LieGroupMorphism, TangentLieAlgebra, VectorFieldBracket, ManifoldTangentMap (hard)
  • 12.2 Highest raw quotient criterion: RawIteratedDifferenceQuotient, ExtendedDifferenceQuotient, ConceptCk (hard)
  • Lemma 12.3: RawIteratedDifferenceQuotient, ExtendedDifferenceQuotient, ConceptCk (hard)
  • §13.1 Continuous inverse algebra examples: ContinuousInverseAlgebra, ConceptLieGroup, ContinuousFunctionAlgebra (hard)
  • Proposition 13.1: SupportedContinuousMapGroup, UniformMapTopology, ConceptLieGroup, LieStructureOnGroup (hard)
  • Proposition 13.2: SupportedCrMapGroup, CompactOpenCrTopology, TestFunctionGroup, LocallyConvexDirectLimit, ConceptLieGroup (hard)
  • §13.3 Diffeomorphism groups: ConceptDiffeomorphism, CompactOpenCrTopology, CompactSupportVectorFields, DiffeomorphismGroupStructure (hard)
  • §13.4 Direct limit groups: ConceptLieGroup, LieGroupMorphism, ClosedSubmanifold, LocallyConvexDirectLimit, DirectLimitGroup (hard)

Selected references

  • Differential Calculus, Manifolds and Lie Groups over Arbitrary Infinite Fields, arXiv:math/0303300v1, https://arxiv.org/abs/math/0303300v1
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Quantum Information·Captain: Goku

Lie groups over non-discrete topological fieldsResearch Paper

Motivation

We generalize the classical construction principles of infinite-dimensional real (and complex) Lie groups to the case of Lie groups over non-discrete topological fields. In particular, we discuss linear Lie groups, mapping groups, test function groups, diffeomorphism groups, and weak direct products of Lie groups. The specific tools of differential calculus required for the Lie group constructions are developed. Notably, we establish differentiability properties of composition and evaluation, as well as exponential laws for function spaces. We also present techniques to deal with the subtle differentiability and continuity properties of non-linear mappings between spaces of test functions. Most of the results are independent of any specific properties of the topological vector spaces involved; in particular, we can deal with real and complex Lie groups modeled on non-locally convex spaces.

This mission is the statement-level formalization of Lie groups over non-discrete topological fields (arXiv:math/0408008v1). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

13 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is The ordinary difference quotient and its continuous extension (Numbered assertion 1.8, PDF p. 14). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

111 results of the paper are not stated yet, because the library lacks an interface they need:

  • Numbered assertion 1.7: Canonical iterated extended-quotient domains and values (hard)
  • Proposition 1.18: ExtendedDifferenceDomain, BGNLieGroup, BGNManifoldCrMap, BGNManifold (hard)
  • Proposition 2.2: The actual BGN Lie structure on the open unit submanifold (hard)
  • Numbered assertion 3.2: Uniform-convergence topology on supported continuous maps and ultrametric local convexity (hard)
  • Proposition 3.3: SupportedContinuousMaps, ParameterizedPushforward, ExtendedDifferenceDomain (hard)
  • Corollary 3.4: SupportedContinuousMaps, ParameterizedPushforward, ExtendedDifferenceDomain (hard)
  • Corollary 3.5: SupportedContinuousMaps, ParameterizedPushforward, ExtendedDifferenceDomain (hard)
  • Remark 4.2: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.3: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.4: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.5: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.6: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.9: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Remark 4.10: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.11: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.12: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.13: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.14: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 4.15: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Proposition 4.16: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, ParameterizedPushforward (hard)
  • Proposition 4.19: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, MackeyComplete, MackeyCauchySequence, UltrametricLocalConvexity, IteratedTangentDerivativeTopology, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, SupportedCrMaps (hard)
  • Proposition 4.20: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, SupportedCrMaps, ParameterizedPushforward (hard)
  • Corollary 4.21: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, SupportedCrMaps, ParameterizedPushforward (hard)
  • Lemma 4.22: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint (hard)
  • Proposition 4.23: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint, ParameterizedPushforward (hard)
  • Lemma 4.24: CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, SupportedCrMaps (hard)
  • Paper seed, pinned to Proposition 5.1: supported mapping groups and tangent bracket: SupportedMappingGroup, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BGNLieGroup, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential (hard)
  • Proposition 5.7: SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Numbered assertion 6.3: BoxDirectSumTopology (hard)
  • Numbered assertion 6.4: BoxDirectSumTopology, UltrametricLocalConvexity (hard)
  • Numbered assertion 6.5: BoxDirectSumTopology, OpenDirectSumBox (hard)
  • Remark 6.6: BoxDirectSumTopology, UltrametricLocalConvexity (hard)
  • Remark 6.7: BoxDirectSumTopology, UltrametricLocalConvexity (hard)
  • Lemma 6.8: BoxDirectSumTopology, ReorderedDifferenceQuotient, ExtendedDifferenceQuotient, ExtendedDifferenceDomain (hard)
  • Proposition 6.9: BoxDirectSumTopology, ReorderedDifferenceQuotient, ExtendedDifferenceQuotient, ExtendedDifferenceDomain, OpenDirectSumBox (hard)
  • Proposition 6.10: BoxDirectSumTopology, OpenDirectSumBox, ExtendedDifferenceDomain (hard)
  • Remark 6.11: BoxDirectSumTopology, AffineAtInfinityGroup, DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, CompactOpenCr, CrMappingSpace (hard)
  • Proposition 7.1: WeakDirectProductLieChart, BGNLieGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, OpenDirectSumBox, BoxDirectSumTopology (hard)
  • Lemma 7.2: WeakDirectProductLieChart, BGNLieGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, OpenDirectSumBox, BoxDirectSumTopology (hard)
  • Lemma 8.3: BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, LocalFieldManifoldBall (hard)
  • Lemma 8.1: BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain (hard)
  • Lemma 8.5: BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain (hard)
  • Lemma 8.7: BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ClopenPartitionOfUnity (hard)
  • Lemma 8.8: BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ClopenPartitionOfUnity (hard)
  • Lemma 8.10: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology (hard)
  • Proposition 8.13: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, TestFunctionTVSDirectLimitTopology, TestFunctionLocallyConvexLimitTopology, UltrametricLocalConvexity (hard)
  • Remark 8.15: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, TestFunctionLocallyConvexLimitTopology, UltrametricLocalConvexity (hard)
  • Remark 8.17: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, BGNVectorBundle, BGNTangentBundle, DirectionalDifferential, CompactSupportVectorFields, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection (hard)
  • Example 8.19: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, PatchedVectorSpace (hard)
  • Proposition 8.21: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, PatchedMap, PatchedVectorSpace (hard)
  • Proposition 8.22: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, ParameterizedPushforward, CompactImageConstraint (hard)
  • Corollary 8.23: TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology, ParameterizedPushforward (hard)
  • Proposition 9.1: TestFunctionGroup, BGNLieGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, BoxDirectSumTopology (hard)
  • Theorem 10.4: LocallyAlmostLocalMap, AlmostLocalMap, TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, BoxDirectSumTopology (hard)
  • Proposition 11.1: FunctionSpaceEvaluationAndComposition, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint (hard)
  • Proposition 11.2: FunctionSpaceEvaluationAndComposition, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint, DirectionalDifferential, SupportedCrMaps (hard)
  • Proposition 11.3: FunctionSpaceEvaluationAndComposition, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint, DirectionalDifferential (hard)
  • Lemma 11.4: FunctionSpaceEvaluationAndComposition, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint (hard)
  • Lemma 12.1: FunctionSpaceCurrying, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Proposition 12.2: FunctionSpaceCurrying, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 12.5: FunctionSpaceCurrying, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, ConvenientKSmooth, ConvenientOpenTopology (hard)
  • Proposition 12.6: FunctionSpaceCurrying, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, ConvenientKSmooth, ConvenientOpenTopology (hard)
  • Proposition 13.2: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, LocalFieldManifoldBall, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Lemma 13.7: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, LocalFieldManifoldBall, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, CompactOpenCr, CrMappingSpace, BoxDirectSumTopology (hard)
  • Lemma 13.8: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, LocalFieldManifoldBall (hard)
  • Lemma 13.9: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, LocalFieldManifoldBall, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Lemma 13.10: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, WeakDirectProductLieChart, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, OpenDirectSumBox, BoxDirectSumTopology, LocalFieldManifoldBall (hard)
  • Lemma 13.11: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, WeakDirectProductLieChart, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, OpenDirectSumBox, BoxDirectSumTopology, LocalFieldManifoldBall (hard)
  • Theorem 13.12: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, WeakDirectProductLieChart, BGNLieAlgebraFunctor, BGNTangentMap, BGNTangentBundle, DirectionalDifferential, ExtendedDifferenceQuotient, OpenDirectSumBox, BoxDirectSumTopology, LocalFieldManifoldBall, CompactSupportVectorFields, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, CompactOpenCr, CrMappingSpace (hard)
  • Remark 13.14: DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, BGNLieGroup, CompactSupportDiffeomorphisms, CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, FunctionSpaceEvaluationAndComposition, CompactImageConstraint (hard)
  • Numbered assertion 14.2: CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Numbered assertion 14.3: CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology (hard)
  • Numbered assertion 14.5: ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, DirectionalDifferential, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, CompactOpenCr, CrMappingSpace, BoxDirectSumTopology, TestFunctionBoxTopology, CompactSupportCrMaps, SupportedCrMaps (hard)
  • Proposition 14.6: NaturalDiffeomorphismManifold, CompactSupportDiffeomorphisms, DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNLieGroup (hard)
  • Lemma 14.17: CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient (hard)
  • Lemma 14.18: CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle (hard)
  • Proposition 14.19: NaturalDiffeomorphismManifold, CompactSupportDiffeomorphisms, DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNLieGroup (hard)
  • Proposition 14.21: NaturalDiffeomorphismManifold, CompactSupportDiffeomorphisms, DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNLieGroup (hard)
  • Remark 14.22: NaturalDiffeomorphismManifold, CompactSupportDiffeomorphisms, DiffeomorphismGroup, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactSupportEndomorphismChart, CompactSupportEndomorphismMonoid, CompactSupportCrMaps, SupportedCrMaps, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, TestFunctionBoxTopology, BoxDirectSumTopology, ProjectiveFiniteOrderTopology, CompactSupportVectorFields, BGNTangentBundle, DirectionalDifferential, SectionBoxTopology, SupportedCrSections, CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNLieGroup (hard)
  • Lemma A.1: IteratedTangentDerivativeTopology, BGNTangentMap, BGNTangentBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, DirectionalDifferential, ExtendedDifferenceQuotient, CompactOpenCr, CrMappingSpace (hard)
  • Lemma A.2: IteratedTangentDerivativeTopology, BGNTangentMap, BGNTangentBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, DirectionalDifferential, ExtendedDifferenceQuotient, CompactOpenCr, CrMappingSpace (hard)
  • Lemma A.3: IteratedTangentDerivativeTopology, BGNTangentMap, BGNTangentBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, DirectionalDifferential, ExtendedDifferenceQuotient, CompactOpenCr, CrMappingSpace (hard)
  • Lemma A.4: Represented weak interval integrals in complete arbitrary locally convex spaces (hard)
  • Lemma A.5: Weak-integral domain with all partial directional derivative integrals and induced derivative topology (hard)
  • Lemma C.1: FunctionSpaceEvaluationAndComposition, CompactOpenCr, CrMappingSpace, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, ExtendedDifferenceQuotient, CompactImageConstraint (hard)
  • Theorem D.1: Mackey completeness and ultrametric local convexity in the source topology (hard)
  • Lemma E.1: The six concrete Boman target classes including Mackey completeness and ultrametric local convexity (hard)
  • Theorem E.2: Mackey-complete ultrametric locally convex targets and the universal scalar Boman premise (hard)
  • Remark F.2: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Lemma F.6: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Remark F.8: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, UltrametricLocalConvexity (hard)
  • Lemma F.9: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Theorem F.11: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, FibrePreservingBundleMap, ParameterizedPushforward (hard)
  • Numbered assertion F.12: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, WhitneySumBundle (hard)
  • Corollary F.13: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Lemma F.15: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SupportedCrSections (hard)
  • Lemma F.16: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient (hard)
  • Lemma F.18: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology (hard)
  • Proposition F.19: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, SectionTVSDirectLimitTopology, SectionLocallyConvexLimitTopology, UltrametricLocalConvexity (hard)
  • Remark F.20: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, SectionLocallyConvexLimitTopology, UltrametricLocalConvexity (hard)
  • Remark F.21: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, PatchedVectorSpace (hard)
  • Lemma F.22: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionImageConstraint, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology (hard)
  • Theorem F.23: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionImageConstraint, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, FibrePreservingBundleMap, ParameterizedPushforward (hard)
  • Corollary F.24: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionImageConstraint, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, FibrePreservingBundleMap (hard)
  • Remark F.25: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionImageConstraint, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, FibrePreservingBundleMap (hard)
  • Numbered assertion F.26: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology, WhitneySumBundle (hard)
  • Corollary F.27: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology (hard)
  • Remark F.28: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, BundleOfTopologicalModules, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology (hard)
  • Theorem F.30: CompactOpenCrSectionTopology, CrSection, BGNVectorBundle, BGNManifoldCrMap, BGNManifold, ExtendedDifferenceDomain, CompactOpenCr, CrMappingSpace, ExtendedDifferenceQuotient, AlmostLocalSectionMap, SectionBoxTopology, SupportedCrSections, BoxDirectSumTopology (hard)
  • 10.3: local maps are almost local (explicit assertion): Germ and patch predicates on the actual box-topologized compact-support mapping spaces (hard)
  • F.29: local maps are almost local (explicit assertion): Germ and patch predicates on actual compact-support section spaces (hard)

Selected references

  • Lie groups over non-discrete topological fields, arXiv:math/0408008v1, https://arxiv.org/abs/math/0408008v1
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Operator Isomorphisms on Hilbert Space Tensor ProductsResearch Paper

Motivation

This article presents an isomorphism between two operator algebras L1L_1L1​ and L2L_2L2​ where L1L_1L1​ is the set of operators on a space of Hilbert-Schmidt operators and L2L_2L2​ is the set of operators on a tensor product space. We next compare our isomorphism to a well-known result called Choi's isomorphism theorem. The advantage of Choi's isomorphism is that it takes completely positive maps to positive operators. One advantage of our isomorphism is that it applies to infinite dimensional Hilbert spaces, while Choi's isomorphism only holds for finite dimensions. Also, our isomorphism preserves operator products while Choi's does not. We close with a brief discussion on some uses of our isomorphism.

This mission is the statement-level formalization of Operator Isomorphisms on Hilbert Space Tensor Products (arXiv:2010.15901v1). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

5 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Lemma 1.3: formula for a basis conjugation (Lemma 1.3, PDF p. 3). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

19 results of the paper are not stated yet, because the library lacks an interface they need:

  • Theorem 1.7: the operator C*-algebra isomorphisms R and S: The complete realized rectangular HS Hilbert space and the prescribed bounded maps J_A, J_A*, R, S (hard)
  • Theorem 1.1 (background attributed to [3]): matrix-unit basis and three equivalent conditions: Theorem 1.1 (background attributed to [3]): matrix-unit basis and three equivalent conditions (source-ambiguity)
  • Theorem 1.2: basis vectorization is unitary, with explicit adjoint: Complete realized HS(H1,H2), its matrix-unit basis, and the bounded series-defined J_A (hard)
  • Lemma 1.5: rank-one operators and simple tensors, with conjugation: Rank-one elements of realized HS(H1,H2), J_A and its Hilbert adjoint (hard)
  • Corollary 1.6: change of orthonormal bases: Two independently constructed HS vectorizations for the reference and new bases (hard)
  • Lemma 1.8: finite-family positivity inequality for R: The prescribed R between endomorphism algebras of the realized HS and completed tensor spaces (hard)
  • Theorem 1.9: R preserves the HS class and HS inner product: Nested realized HS Hilbert spaces and the restriction of source R (hard)
  • Lemma 2.1: the one-basis vectorization equals J_A: HS-domain one-basis vectorization T_B and independently defined two-basis J_A (hard)
  • Lemma 2.3: slice expansion of T_B adjoint: The bounded HS-domain T_B and HS-valued rank-one slice series (hard)
  • Unnumbered claim: the spectrum characterization of conjugation: Unnumbered claim: the spectrum characterization of conjugation (source-ambiguity)
  • Unnumbered consequence: positivity and complete positivity of R and S: Prescribed R and S on the full bounded endomorphism algebras of the HS Hilbert space and completed tensor space (hard)
  • Unnumbered analogue of Theorem 1.9 for S: Nested realized HS Hilbert spaces and source S restricted to the HS class (hard)
  • Unnumbered comparison: Choi fails product preservation and differs from R: Compatible finite HS Hilbert realization, prescribed R, and unnormalized input-first Choi map (hard)
  • Discussion: concatenation of the displayed Kraus maps: Bounded HS endomorphisms and actual HS-norm-convergent Kraus sandwich series (hard)
  • Equations (3.1)–(3.2): R of a represented Kraus map: HS-valued Kraus representation, constructed M_alpha and source R (hard)
  • Discussion: adapted product vectors and their rank-one projections under S: Adapted complete bases, source J_A*, and S acting on rank-one projections (hard)
  • Discussion: Schmidt coefficients detect entanglement and give the J_A* image: Finite realized HS Hilbert space and J_A* for the supplied Schmidt bases (hard)
  • Discussion: the printed general product-operator action under S: Discussion: the printed general product-operator action under S (source-ambiguity)
  • Discussion: the final printed HS expansion: Discussion: the final printed HS expansion (source-ambiguity)

Selected references

  • Operator Isomorphisms on Hilbert Space Tensor Products, arXiv:2010.15901v1, https://arxiv.org/abs/2010.15901v1
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Optics of Nonuniformly Moving MediaResearch Paper

Motivation

A moving dielectric appears to light as an effective gravitational field. At low flow velocities the dielectric acts on light in the same way as a magnetic field acts on a charged matter wave. We develop in detail the geometrical optics of moving dispersionless media. We derive a Hamiltonian and a Lagrangian to describe ray propagation. We elucidate how the gravitational and the magnetic model of light propagation are related to each other. Finally, we study light propagation around a vortex flow. The vortex shows an optical Aharonov--Bohm effect at large distances from the core, and, at shorter ranges, the vortex may resemble an optical black hole.

This mission is the statement-level formalization of Optics of Nonuniformly Moving Media (arXiv:physics/9906038v3). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

22 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Ray Hamiltonian, comoving speed, and wave-number independence (§III B, (30)–(38): ray Hamiltonian, comoving speed and independence of wave number, PDF p. 5). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

4 results of the paper are not stated yet, because the library lacks an interface they need:

  • §II, (2)–(4): first-order scalar laboratory wave equation: The claimed transformation of (2)/(3) into the printed differential equation (4). (source-ambiguity)
  • §II, (17): magnetic Schrödinger wave equation: Equality of the stationary optical wave equation with (-i grad+(n^2-1)omegau/c^2)^2 psi=n^2omega^2psi/c^2. (source-ambiguity)
  • §IV C, (87)–(88): claimed second-order vortex light deflection: The source claims phi_D approximately (pi/2)(n^2-1)W^2/(b^2c^2), equivalently n^2nu_AB^2lambda^2/(8pi*(n^2-1)*b^2), for vortex scattering. (source-ambiguity)
  • §IV D and IV E: optical black-hole capture claim: A global characterization of the initial data/angular-momentum interval of rays falling into the ideal vortex core, and the claimed interpretation as an optical black hole. (source-ambiguity)

Selected references

  • Optics of Nonuniformly Moving Media, arXiv:physics/9906038v3, https://arxiv.org/abs/physics/9906038v3
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Optimal Teleportation Based on Bell MeasurementResearch Paper

Motivation

We study optimal teleportation based on the Bell measurements. An explicit expression for the quantum channel associated with the optimal teleportation with an arbitrary mixed state resource is presented. The optimal transmission fidelity of the corresponding quantum channel is calculated and shown to be related to the fully entangled fraction of the quantum resource, rather than the singlet fraction as in the standard teleportation protocol.

This mission is the statement-level formalization of Optimal Teleportation Based on Bell Measurement (arXiv:quant-ph/0208015v2). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

3 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Optimal Bell-measurement teleportation channel and attained mean fidelity (Theorem 3, Eqs.(14)-(15): optimal Bell-measurement channel and maximal mean fidelity (abstract seed), PDF p. 6). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Selected references

  • Optimal Teleportation Based on Bell Measurement, arXiv:quant-ph/0208015v2, https://arxiv.org/abs/quant-ph/0208015v2
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Noncommutative Lp modulesResearch Paper

Motivation

We construct classes of von Neumann algebra modules by considering ``column sums" of noncommutative L^p spaces. Our abstract characterization is based on an L^{p/2}-valued inner product, thereby generalizing Hilbert C*-modules and representations on Hilbert space. While the (single) representation theory is similar to the L^2 case, the concept of L^p bimodule (p not 2) turns out to be nearly trivial.

This mission is the statement-level formalization of Noncommutative Lp modules (arXiv:math/0301044v2). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

1 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is Compatible bounded operator nets have a strong limit (corrected infinite endpoint) (unnumbered-infinite-exponent-compatible-net, PDF p. 5). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

37 results of the paper are not stated yet, because the library lacks an interface they need:

  • Lemma 1.1: Actual Haagerup Lp quasi-norm and strong bounded-algebra action; positive spectrum norm images (hard)
  • Lemma 1.2: Normal-functional densities, supports, and quasi-norm closure of left/right Haagerup cyclic ranges (hard)
  • unnumbered-polar-multiplier-spectrum: Closed strong product and polar decomposition in the actual Haagerup Lp module (hard)
  • Lemma 1.3: Finite-positive-exponent Haagerup action topologies and functional density powers (hard)
  • Lemma 1.4: Actual complete Haagerup quasi-Lr space and right multiplication by projections (hard)
  • Theorem 1.5: Actual Haagerup Lp/Lq/Lr spaces, closed strong product, and bounded complex-linear right-module maps (hard)
  • Corollary 1.6: Bounded complex-linear endomorphisms of actual quasi-Lp and both multiplication action images (hard)
  • Corollary 1.7: Diffuse projection lattice and actual bounded cross-exponent right-module Hom (hard)
  • Proposition 2.2: Actual L^(p/2)-valued pre-inner-product module, affiliated square roots and products (hard)
  • Theorem 2.5: Actual abstract Lp modules, their inherited completions, and arbitrary-index principal column modules (hard)
  • Theorem 3.1: Canonical strong/weak Hilbert-module envelopes, self-duality and arbitrary ultraweak column sums (hard)
  • unnumbered-strong-hilbert-module-envelope: Canonical strong Hilbert C*-module completion, principal envelope and dense embedding (hard)
  • Lemma 3.2: Faithful strictly semifinite weight densities and actual weight-bounded Lp module vectors (hard)
  • Lemma 3.3: Constructed weight-bounded vector set D_phi and inherited quasi-norm topology (hard)
  • unnumbered-column-sum-realization: Completion of finite-support Lp columns and convergence of their positive inner-product sums (hard)
  • unnumbered-improved-module-norm: Independently defined complete Lp inner-product modules at all positive exponents (hard)
  • unnumbered-orthogonal-column-complement: Lp module orthogonality, closed linear module span, and induced embedded Lp submodules (hard)
  • Proposition 4.2: Banach column ultrapower, Raynaud algebra and canonical p and p/2 identifications (hard)
  • unnumbered-ultrapower-column-inclusion: Canonical column ultrapower inclusion, coordinatewise projection and properness witness (hard)
  • Proposition 5.1: Arbitrary-cardinal Haagerup amplified columns, corner actions and bounded commutants (hard)
  • Corollary 5.2: Bounded invertible maps of actual amplified Lp modules and projection comparison (hard)
  • Corollary 5.3: Rectangular Haagerup multiplier corners and all bounded cross-exponent module maps (hard)
  • unnumbered-II1-module-dimension: Normalized amplified II1 trace, projection-class dimension and countable column sums (hard)
  • unnumbered-module-isomorphism-monoid: Isomorphism classes of countably generated actual Lp modules and projection-class addition (hard)
  • unnumbered-module-stabilization: Actual countable Haagerup columns, column sum and spatial module isomorphism (hard)
  • unnumbered-contragredient-involution: Constructed left/right Lp module structures on conjugate spaces and affiliated adjoint identification (hard)
  • unnumbered-relative-tensor-existence-uniqueness: A pinned functor class with sufficient enrichment/normality or sum-preservation axioms (source-ambiguity)
  • Proposition 5.6: Canonical sum-preserving relative tensor product and actual rectangular Haagerup Lr corner (hard)
  • Lemma 6.1: Actual faithful Lp bimodule actions and induced amplified-corner right-action embedding (hard)
  • Proposition 6.3: Centers and induced action images of an actual faithful two-sided Lp bimodule (hard)
  • unnumbered-scalar-module-rigidity: Actual Haagerup Lp norm and compatible scalar-valued Hilbert-module structures (hard)
  • Proposition 6.6: Induced normal corner inclusion, actual row-module presentation, Murray-von Neumann subequivalence (hard)
  • Proposition 6.7: Finite-algebra amplified projection strict comparison and faithful Lp bimodule presentations (hard)
  • Proposition 6.8: Measurable Hilbert fields and actual Lp direct integrals with both pointwise actions (hard)
  • Theorem 6.10: Independent W*-Morita equivalence and actual faithful countably generated Haagerup bimodule existence (hard)
  • Theorem 6.9: Canonical common-center abelian projection, actual bimodule restrictions and variable-fiber p-direct integrals (hard)
  • unnumbered-representation-category-equivalence: Canonical tensor functors on actual Lp representation categories and well-typed conjugate tensor identities (hard)

Selected references

  • Noncommutative Lp modules, arXiv:math/0301044v2, https://arxiv.org/abs/math/0301044v2
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General Security Definition and Composability for Quantum & Classical ProtocolsResearch Paper

Motivation

We generalize the universally composable definition of Canetti to the Quantum World. The basic idea is the same as in the classical world. The main contribution is that we unfold the result in a new model which is well adapted to quantum protocols. We also simplify some aspects of the classical case. In particular, the case of protocols with an arbitrary number of layers of sub-protocols is naturally covered in the proposed model.

This mission is the statement-level formalization of General Security Definition and Composability for Quantum & Classical Protocols (arXiv:quant-ph/0409062v2). Every numbered result of the paper was scanned. The results stated here are open sorry goals, ready for solvers to prove.

What is formalized

1 statements of the paper are in Lean 4 (Mathlib 0df444a). The goal theorem is All parity-bit biases control the Euclidean distance of string laws (§2.4, unnumbered parity bound, PDF p. 5). The milestones are the other numbered results, in the paper's order, each quoting the paper.

The paper's own objects are the definition item of this mission. Objects shared across papers come from the prove2quantum library and from earlier papers' missions, listed as references.

Provenance: prove2quantum's pipeline drafted each statement (gpt-6.1-sol on Stanford's Sherlock cluster). A blind read-back, written without seeing the paper, is attached to every item. An independent moderator compared each statement against the paper and passed the whole paper without edits.

Deferred results

9 results of the paper are not stated yet, because the library lacks an interface they need:

  • Theorem 1: both scenarios: Bound-circuit execution, security families, typed tree substitution, and uniform computational resources (hard)
  • Theorem 2: Environment-indexed error and recursively constructed hybrid replacement history (hard)
  • §2.4, test-string composition: Operational string-output laws with one common bounded triangle comparison (hard)
  • §2.5, forwarding applications: Typed forwarding-application construction with always-active Eve (hard)
  • Appendix C, equivalence: Original and alternative security with typed direct application access (hard)
  • Appendix C, first step: Probe-register channel mediation and simulator transport (hard)
  • Appendix C, second step: Actual Adv-P gate subdivision defining Dummy, SAdv, and Eprime (hard)
  • §2.5–2.6, concrete bias; compare pp.4,16: A source-consistent bit-valued rejection rule for the CT/BC attack (source-ambiguity)
  • Appendix E, proposed DAG-to-tree reorganization: A quantified persistence condition for shared functionality and a last-caller boundary in the proposed rewrite (source-ambiguity)

Selected references

  • General Security Definition and Composability for Quantum & Classical Protocols, arXiv:quant-ph/0409062v2, https://arxiv.org/abs/quant-ph/0409062v2
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