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A finite boosted atlas with uniform collar inputs

Proved
OAI.CKSLorentz.exists_uniform_boost_collar_atlas

by wurtle · Nov 4, 2026 · Mathlib 0df444a (Lean v4.33.1)

cks-bondi-penrosegeneral-relativityoai-math

Let ∥p∥<e\|p\|<e∥p∥<e, let A,BA,BA,B be spatial tensor fields and let old assign to each direction n∈S2n\in S^2n∈S2 a CKS tensor patch containing nnn in its region and realizing (A,B)(A,B)(A,B). Then there are a finite set s⊂S2s\subset S^2s⊂S2, angular patches PnP_nPn​, radii δn\delta_nδn​, a radius R>0R>0R>0, a compact set KKK of positive-definite three-jets and a constant C≥0C\ge 0C≥0 such that for each n∈sn\in sn∈s the boosted fields form a SpatialBoostPatch on the ball of radius 2δn2\delta_n2δn​, they satisfy UniformCollarInput K C R on the closed ball of radius δn\delta_nδn​ around the chart image of nnn, and these balls, pulled back to the sphere, cover S2S^2S2.

Formal statement. In the scope of the preamble:

theorem exists_uniform_boost_collar_atlas {e : ℝ} {p : E} (he : ‖p‖ < e)
    (A B : SpatialTensor) (old : Sphere → CKSTensorPatch)
    (hold : ∀ n, n ∈ (old n).patch.sphereRegion (old n).region)
    (hreal : ∀ n, (old n).Realizes A B) :
    ∃ (s : Finset Sphere) (P : Sphere → SmoothAngularPatch) (δ : Sphere → ℝ)
      (R : ℝ) (K : Set MatrixThreeJet) (C : ℝ),
      0 < R ∧ IsCompact K ∧
      (∀ q ∈ K, Matrix.PosDef (fun i k => (q i k).1.1)) ∧ 0 ≤ C ∧
      (∀ n ∈ s, SpatialBoostPatch e p he A B (old (boundary e p he n))
        (P n) ((P n).chart n) (2*δ n) R) ∧
      (∀ n ∈ s, (boostSourceFields e p A B (old (boundary e p he n)) (P n)).UniformCollarInput
        K C R (Metric.closedBall ((P n).chart n) (δ n))) ∧
      (∀ q : Sphere, ∃ n ∈ s, q ∈ (P n).sphereRegion (Metric.ball ((P n).chart n) (δ n)))

Formalization Note The statement is verbatim from lean/OAI/Geometry/Relativity/CKS/ConstructedOuterMetric.lean, lines 5086-5120, in OpenAI's openai/math at commit adc7f12 (Apache-2.0), formalizing part of the construction in the preprint Area-controlled end replacement and the Bondi–Penrose inequality in the CKS class (OpenAI, September 27, 2026). It is a supporting lemma for OAI.CKSSourceExterior.area_controlled_end_replacement. The definitions it mentions are those of Definitions.Def_CKSBondiPenrose and Definitions.Def_CKSEndReplacementSupport.

Preamble
import Mathlib
import Definitions.Def_CKSBondiPenrose
import Definitions.Def_CKSEndReplacementSupport

namespace OAI

noncomputable section
namespace CKSSphericalChart
noncomputable section
open Set Filter CKSSphericalHarmonics CKSInducedSphere CKSBending
open scoped Topology Matrix

end
end CKSSphericalChart

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped InnerProductSpace RealInnerProductSpace ContDiff Manifold Topology
open Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped InnerProductSpace RealInnerProductSpace ContDiff Manifold Topology
open Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped RealInnerProductSpace ContDiff

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped InnerProductSpace RealInnerProductSpace ContDiff

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped RealInnerProductSpace ContDiff
open Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open scoped RealInnerProductSpace ContDiff
open Set

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice
open scoped ContDiff

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

namespace FiniteLogDecay
variable {j : ℕ} {q r : ℝ} {U : Set Point} {f g : Point → ℝ}

end FiniteLogDecay
end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff
namespace FiniteLogDecay

end FiniteLogDecay
end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set
open scoped ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus
open scoped Topology ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set
open scoped ContDiff

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set Filter CKSCalculus CKSAngularSlice
open scoped ContDiff Topology

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSCalculus CKSAngularSlice

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSCalculus CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSCalculus CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

namespace SmoothAngularPatch

end SmoothAngularPatch

attribute [local instance] stereoDimension

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

attribute [local instance] stereoDimension

namespace SmoothAngularPatch

end SmoothAngularPatch
end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice
attribute [local instance] real_continuousAdd

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped ContDiff Topology

namespace SmoothAngularPatch

end SmoothAngularPatch

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice CKSCalculus Set Filter
open scoped Topology ContDiff

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSCalculus Set Filter
open scoped ContDiff Topology

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry Set

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set Filter
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped Topology ContDiff

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Topology

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry
open CKSAngularGeometry (metricBlock AmbientMat)

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry Set
open CKSAngularGeometry (metricBlock AmbientMat)

end
end CKSLorentz

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open CKSCalculus CKSAngularSlice
open scoped Topology ContDiff Matrix.Norms.Elementwise

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set CKSAngularSlice CKSCalculus
open scoped ContDiff Matrix.Norms.Elementwise

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Matrix.Norms.Elementwise

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open scoped Matrix.Norms.Elementwise

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped ContDiff Matrix.Norms.Elementwise

end
end CKSLorentz

end

noncomputable section
namespace CKSMixedGeometry
noncomputable section
open Set CKSAngularSlice
open scoped Matrix.Norms.Elementwise

end
end CKSMixedGeometry

end

noncomputable section
namespace CKSLorentz
noncomputable section
open CKSMixedGeometry CKSAngularSlice Set
open scoped Matrix.Norms.Elementwise

Formal statement
theorem exists_uniform_boost_collar_atlas {e : ℝ} {p : E} (he : ‖p‖ < e)
    (A B : SpatialTensor) (old : Sphere → CKSTensorPatch)
    (hold : ∀ n, n ∈ (old n).patch.sphereRegion (old n).region)
    (hreal : ∀ n, (old n).Realizes A B) :
    ∃ (s : Finset Sphere) (P : Sphere → SmoothAngularPatch) (δ : Sphere → ℝ)
      (R : ℝ) (K : Set MatrixThreeJet) (C : ℝ),
      0 < R ∧ IsCompact K ∧
      (∀ q ∈ K, Matrix.PosDef (fun i k => (q i k).1.1)) ∧ 0 ≤ C ∧
      (∀ n ∈ s, SpatialBoostPatch e p he A B (old (boundary e p he n))
        (P n) ((P n).chart n) (2*δ n) R) ∧
      (∀ n ∈ s, (boostSourceFields e p A B (old (boundary e p he n)) (P n)).UniformCollarInput
        K C R (Metric.closedBall ((P n).chart n) (δ n))) ∧
      (∀ q : Sphere, ∃ n ∈ s, q ∈ (P n).sphereRegion (Metric.ball ((P n).chart n) (δ n))) := by
  sorry

end
end CKSLorentz
end
end OAI
Source
https://github.com/openai/math/blob/adc7f1241b42e322a6451854ab7e4b4c146bf78a/lean/OAI/Geometry/Relativity/CKS/ConstructedOuterMetric.lean#L5086-L5120 ; preprint preprints/Area-controlled-end-replacement-and-the-Bondi-Penrose-inequality-in-the-CKS-class-September-27-2026/paper.pdf in the same repository

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