Banach embedding properties of non-commutative L^p-spacesResearch Paper
Motivation
Let N and M be von Neumann algebras. It is proved that L^p(N) does not Banach embed in L^p(M) for N infinite, M finite, 1 < or = p < 2. The following considerably stronger result is obtained (which implies this, since the Schatten p-class C_p embeds in L^p(N) for N infinite). Theorem: Let 1 < or = p < 2 and let X be a Banach space with a spanning set (x_{ij}) so that for some C < or = 1: (i) any row or column is C-equivalent to the usual ell^2-basis; (ii) (x_{i_k,j_k}) is C-equivalent to the usual ell^p-basis, for any i_1 < i_2 < ... and j_1 < j_2 < ... . Then X is not isomorphic to a subspace of L^p(M), for M finite. Complements on the Banach space structure of non-commutative L^p-spaces are obtained, such as the p-Banach-Saks property and characterizations of subspaces of L^p(M) containing ell^p isomorphically. The spaces L^p(N) are classified up to Banach isomorphism, for N infinite-dimensional, hyperfinite and semifinite, 1 < or = p< infty, p not= 2. It is proved that there are exactly thirteen isomorphism types; the corresponding embedding properties are determined for p < 2 via an eight level Hasse diagram. It is also proved for all 1 < or = p < infty that L^p(N) is completely isomorphic to L^p(M) if N and M are the algebras associated to free groups, or if N and M are injective factors of type III_lambda and III_{lambda'} for 0 < lambda, lambda' < or = 1.
This mission is the statement-level formalization of Banach embedding properties of non-commutative L^p-spaces (arXiv:math/0005150v1). 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 Uniformly convex spaces admit finite almost suppression-unconditional selections (Corollary 4.5, PDF p. 28). 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
62 results of the paper are not stated yet, because the library lacks an interface they need:
- Abstract theorem: generalized Schatten matrices do not embed in finite Lp: Actual Lp of an arbitrary finite von Neumann algebra, with its Banach norm, together with infinite generalized Schatten spanning matrices and Banach embeddings. (hard)
- Abstract and introduction: infinite-algebra Lp does not embed into finite-algebra Lp: Actual Lp for finite and algebraically infinite von Neumann algebras, and arbitrary-real-p Schatten class with its Banach embedding into the latter. (hard)
- Theorem 1.1: Actual finite tracial Lp space and normal faithful tracial state; infinite matrix rows, columns, individually unconditional diagonals and the all-further-subsequences decay conclusion. (hard)
- Corollary 1.2: Actual finite tracial Lp space and normal faithful tracial state; spanning generalized Schatten matrices, arbitrary-real-p Cp and Banach non-embeddings. (hard)
- Corollary 1.3: Actual finite tracial Lp space and normal faithful tracial state; the completion Rad Cp in the first-moment Rademacher-average norm, not the pth-mean norm. (hard)
- Corollary 1.4: A complete finite GCp-space model and ENNReal Banach–Mazur infimum over all such spaces and commutative Lp subspaces, with the common p,lambda uniform threshold. (hard)
- Remark after Corollary 1.4: arbitrary finite algebras: Countable joins of left/right supports of actual measurable affiliated operators, their sigma-finite corners, finite-trace renormalization, and corner Lp isometries. (hard)
- Lemma 2.3: all moduli inequalities, equalities and spectral truncation: Actual measurable affiliated operator algebra, trace on absolute real powers, all four moduli, spectral projections, and decreasing rearrangements with correct operator domains. (hard)
- Remark 2 after Weyl sublemma: semifinite extension of Lemma 2.3: The same complete modulus and spectral-calculus construction for an atomless semifinite trace without probability normalization. (hard)
- Proposition 2.5, including its moreover clause: Actual normal predual L1 and its Banach weak topology, absolute value, uniform integrability, spectral tails and normal-functional evaluation on orthogonal projections. (hard)
- Corollary 2.6: Actual normal predual L1 with the sigma(L1,N) weak-topology identification and a uniformly integrable arbitrary-subset predicate. (hard)
- Remark after Corollary 2.6: complemented ell1 subsequence: Actual L1 normal predual, the non-UI modulus limit eta and the disjointization subsequence, with complemented closed spans and quantitative ell1 basis equivalence. (hard)
- Corollary 2.7: Actual tracial Lp, L1-valued absolute pth powers, spectral tail modulus and the bounded-algebra inclusion giving truncation distance. (hard)
- Lemma 3.1: Actual finite tracial Lp and uniform integrability of absolute pth powers. The generic rate predicate alone does not construct either object. (hard)
- Remark 1 after Lemma 3.1: uniform subsequence decay: Actual finite tracial Lp and pth-power uniform integrability, together with a subsequence-uniform convergence threshold. (hard)
- Remark 2 after Lemma 3.1: quantitative Rademacher bound: Actual finite tracial Lp, bounded-operator truncation distance and a Rademacher expectation on these vectors. (hard)
- Lemma 3.2: Actual Lp operator compressions P f P, their pth absolute-power trace, and projections in the ambient finite algebra. (hard)
- Lemma 3.3: Actual Lp projection moduli at varying masses, their symmetric versions and noncommutative compressions. (hard)
- Corollary 3.4: Actual tracial Lp with pth-power uniform integrability and ellp-equivalent subsequences. (hard)
- Remark after Corollary 3.4: complemented span and p=1 extension: Actual tracial Lp and a constructed complemented closed span of the non-UI ellp subsequence, including the unconditional-free p=1 case. (hard)
- Remark after Corollary 3.4: deletion of unconditionality for hyperfinite N: Intended scope of the claimed deletion of unconditionality after Corollary 3.4. (source-ambiguity)
- Corollary 3.5: Actual tracial Lp and uniform integrability of absolute pth powers; its plain all-subsequences limit must not assume weak-null. (hard)
- Lemma 3.6 and immediate isometric embedding: Two distinct genuine quotient constructions: the finite algebra ultrapower and the Banach Lp ultrapower, the closure Yp, their canonical maps, and the trace-induced Lp extension. (hard)
- Lemma 3.7: Actual Lp bounded-truncation distances, with real ultralimits before the column supremum and correct uniform bounds. (hard)
- Theorem 4.1: Actual finite-algebra Lp Banach space and its weak topology; exact column/row/diagonal alternatives, uniform finite ellp representations and required basic or unconditional sequence predicates. (hard)
- Remark after Theorem 4.1: symmetric alternatives: Actual finite-algebra Lp Banach space and its weak topology; exact column/row/diagonal alternatives, uniform finite ellp representations and required basic or unconditional sequence predicates. (hard)
- Theorem 4.2, both cases and hyperfinite strengthening: Actual finite-algebra Lp Banach space and its weak topology; exact column/row/diagonal alternatives, uniform finite ellp representations and required basic or unconditional sequence predicates. (hard)
- Remark after Theorem 4.2: weaker column alternative: Actual finite-algebra Lp Banach space and its weak topology; exact column/row/diagonal alternatives, uniform finite ellp representations and required basic or unconditional sequence predicates. (hard)
- Corollary 4.4: Actual tracial Lp and uniform integrability of pth absolute powers, for weak-null sequences and the joint scalar/subsequence-uniform decay conclusion. (hard)
- Remark after Corollary 4.4: spreading models: Actual tracial Lp and uniform integrability of pth absolute powers, with a genuine asymptotic spreading-model construction. (hard)
- Lemma 4.7: The normal predual of an arbitrary von Neumann algebra and concrete compression of its functionals by projections. (hard)
- Theorem 4.2(b) prime: Actual finite-algebra normal predual and its weak topology; exact column/row/diagonal alternatives, uniform finite ellp representations and required basic or unconditional sequence predicates. (hard)
- Lemma 4.8: Arbitrary-algebra normal predual, compression P f P with its inherited norm, and finite/infinite orthogonal families with extended off-diagonal sums. (hard)
- Lemma 4.9 and quantitative remark: Arbitrary-algebra normal predual and orthogonal compressions; the completed local scalar selection lemma does not provide this predual realization. (hard)
- Complemented spans of relatively disjoint sequences: The actual normal predual and its compressions, with a bounded projection from N_* onto the relatively disjoint closed span. (hard)
- Lemma 4.6 prime: The actual normal predual, orthogonal projection evaluation and the positive limsup modulus of an arbitrary subset of its unit ball. (hard)
- Remark after Lemma 4.6 prime: property V-star: The actual normal predual and its Banach weak topology, allowing bounded non-relatively-weakly-compact subsets and complemented ell1 spans. (hard)
- Proposition 5.1: Infinite Row/Col operator spaces and actual finite-algebra L1 with its standard predual matrix norms and complete embeddings. (hard)
- Unnumbered Proposition: Hilbertian homogeneous operator spaces: Concrete operator-space dual/opposite matrix norms, Hilbertian homogeneity and the actual finite-algebra predual target. (hard)
- Theorem 5.4: all seven equivalences: Actual tracial Lp, all projection/spectral moduli and almost disjoint support, with Banach ellp embedding; all seven equivalences, omitting the p-vs-1 condition at p=1. (hard)
- Theorem 5.4 Remark 1: alternative condition 5-prime: Actual tracial Lp, all projection/spectral moduli and almost disjoint support, with Banach ellp embedding and actual Lq quasi-gauges for every real 0<q<p. (hard)
- Proposition 5.6: Banach–Saks, dichotomy, and subspace characterization: Actual finite-algebra noncommutative Lp and its Banach weak topology, absolute pth powers and UI. Generic HRS rate predicates are constructed locally, but the operator Lp domain is still absent. (hard)
- Introduction consequence of Proposition 5.6: hereditary strong-p subsequences: Actual finite-algebra noncommutative Lp and its Banach weak topology, absolute pth powers and UI. Generic HRS rate predicates are constructed locally, but the operator Lp domain is still absent. (hard)
- Remark after Proposition 5.6: Hilbert endpoint and p>2 rate: Actual finite-algebra noncommutative Lp and its Banach weak topology, absolute pth powers and UI. Generic HRS rate predicates are constructed locally, but the operator Lp domain is still absent. (hard)
- Discussion of the open problem: proved domination and spreading model: Actual finite-algebra noncommutative Lp and its Banach weak topology, absolute pth powers and UI. Generic HRS rate predicates are constructed locally, but the operator Lp domain is still absent. (hard)
- Equivalence of the two open formulations: Actual finite-algebra noncommutative Lp and its Banach weak topology, absolute pth powers and UI. Generic HRS rate predicates are constructed locally, but the operator Lp domain is still absent. (hard)
- Theorem 6.1: thirteen Banach/operator-space isomorphism types: The actual thirteen Banach/operator-space models, hyperfinite semifinite algebras with separable predual, and complete/Banach isomorphism and unique isomorphism-type classification. (hard)
- Theorem 6.2 and Figure 1: complete classification and embedding order: The actual thirteen Banach/operator-space models, hyperfinite semifinite algebras with separable predual, and complete/Banach isomorphism, with the 17-edge embedding reachability classification. (hard)
- Theorem 6.3: Actual infinite Schatten Cp, Bochner Lp(Cp), finite-algebra Lp and direct sums, including the Cp target summand. (hard)
- Lemma 6.4: The actual arbitrary-real-p Schatten Banach space Cp, not just an integer exponent ideal-membership predicate or a finite-dimensional norm. (hard)
- Corollary 6.8: Actual Lp of the hyperfinite II1 factor and actual infinite Schatten Cp, with the Bochner Lp(Cp) target. (hard)
- Theorem 6.9: Actual infinite Schatten Cp, Bochner Lp(Cp), finite-algebra Lp and direct sums, plus Lp(R spatial-tensor B(ell2)), distinct from Bochner Lp(Cp). (hard)
- Lemma 6.10: Actual Lp(R) and Lp/2(R) measurable-operator products and square roots for both row and column square functions. (hard)
- Corollary 6.11: Actual Lp(R spatial-tensor B(ell2)), the matrix-unit tensor map and its induced subspace norm, including row/column and diagonal predicates. (hard)
- Corollary 6.12: Type-II-infinity/III nonzero central summands of arbitrary algebras and actual general Haagerup Lp Banach embeddings. (hard)
- Remark after Corollary 6.12: type II1 obstruction: Type-II1 and type-II/III nonzero central summands with actual general Haagerup Lp Banach embeddings. (hard)
- Corollary 6.14: Actual operator-space matrix norms, their countable operator ellp sum and completely bounded complemented factorization. (hard)
- Theorem 7.1: The genuine preduals of type-II1 and type-II-infinity/III factors, with Banach isomorphisms. (hard)
- Theorem 7.2, both parts: Concrete Powers and Araki–Woods factors, standard dual operator-space preduals, injective type-III0 factors and pairwise algebra nonisomorphism. (hard)
- Theorem 7.3: Concrete free group von Neumann algebras for finite ranks and countably infinite rank, with their genuine operator-space preduals. (hard)
- Lemma 7.4: Actual Kosaki/Haagerup Lp spaces with Pisier matrix norms and the interpolation constructions of i_p and expectation_p from a normal faithful conditional expectation. (hard)
- Theorem 7.5, all three parts: Concrete Powers/Araki–Woods/free-group factors and Haagerup/Kosaki Lp with Pisier matrix norms for every 1<=p<infinity, including p=1. (hard)
Selected references
- Banach embedding properties of non-commutative L^p-spaces, arXiv:math/0005150v1, https://arxiv.org/abs/math/0005150v1