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LeanPool.HighContrastHomogenization.Provider.PolynomialHomogenization.Root.Corrector.SelectedGenerationRoundedEllipsoidWeightedNormBridge

High-contrast homogenization: #

Provider.PolynomialHomogenization.Root.Corrector .SelectedGenerationRoundedEllipsoidWeightedNormBridge

Imported from the Apache-2.0 HighContrastHomogenization development at commit 7a13dbcd8d6609264a713373f5c69ceeac870472.

Weighted norms on a selected rounded generation #

The mixed-order recurrence chooses its rounded coordinate matrix after the analytic constants have been fixed. The matrix remains uniformly close to the normalized reference, so the standard rounded-ellipsoid volume and weighted-norm comparisons hold with the same dimension-only constants.

The Euclidean ball of half the physical radius lies in the pullback for every admissible selected rounded generation.

The selected pullback ellipsoid lies in the Euclidean ball of twice the physical radius.

The selected pullback lies in the canonical dimension-free outer cube.

The selected rounded pullback is monotone in its positive radius.

A positive-radius selected pullback ellipsoid has positive volume.

A positive-radius selected pullback ellipsoid has finite volume.

The canonical outer cube has a dimension-only real volume ratio over a selected pullback ellipsoid.

The selected pullback at the terminal radius has a dimension-only real volume ratio over the interior terminal cube.

Near the terminal radius, selected pullback volumes have a dimension-only ratio.

ENNReal form of the selected near-terminal volume-ratio bound.

Weighted energy on a selected pullback is controlled by its canonical outer origin cube.

Weighted energy on the terminal cube is controlled by the selected pullback at the terminal radius.

theorem HCPolySupport.HighContrast.Root.weightedGradNorm_selectedRoundedPullbackEllipsoid_le_of_near_terminal {d : ℕ} [NeZero d] (geom : RoundedGenerationAnalyticGeometry d) (abar : Mat d) (hS : Matrix.PosDef (symmPart abar)) {r R : ℝ} (hr : 0 < r) (hR : 0 < R) (hrR : r ≤ R) (hnear : R < 400 * ↑d * r) (b : CoeffField d) (F : Vec d → Vec d) :

The selected near-terminal branch closes directly by normalized-domain restriction.

theorem HCPolySupport.HighContrast.Root.weightedGradNorm_roundedCenteredCoefficientAtGeneration_le_of_finiteEnergy {d : ℕ} (l : ℤ) (hl : ↑(kZero d) ≤ l) (aPhysical : CoeffSpace d) (abar : Mat d) (hS : Matrix.PosDef (symmPart abar)) (aRounded : Book.Ch03.CoeffFamily d) (hRoundedAE : ∀ (Q : TriadicCube d), (aRounded.coeffOn Q).toCoeffField =ᵐ[MeasureTheory.volume] roundedCenteredCoefficientAtGeneration l hl abar hS ↑↑aPhysical) (m : ℤ) (u : Book.Ch03.CubeSolution (originCube d m) aRounded) (h : ℤ) (hhm : h ≤ m) (H : ℝ) (hH : 0 ≤ H) (henergy : finiteCenteredCubeSolutionEnergy aRounded m u h ≤ H * finiteCenteredCubeSolutionEnergy aRounded m u m) :

A finite centered-energy estimate lifts to the selected-generation coefficient by the application's almost-everywhere identification.

theorem HCPolySupport.HighContrast.Root.weightedGradNorm_selectedRoundedCenteredPullback {d : ℕ} [NeZero d] (geom : RoundedGenerationAnalyticGeometry d) (abar : Mat d) (hS : Matrix.PosDef (symmPart abar)) {U : Set (Vec d)} (hU : MeasurableSet U) (a : CoeffField d) (F : Vec d → Vec d) :
weightedGradNorm (fun (x : Vec d) => specBound (symmPart abar)⁻¹ • (a x - skewPart abar)) U F = weightedGradNorm (roundedCenteredCoefficientAtGeneration geom.generation ⋯ abar hS a) (matImage (geom.grid (symmPart abar))⁻¹ U) fun (y : Vec d) => matVecMul (geom.grid (symmPart abar)) (F (matVecMul (geom.grid (symmPart abar)) y))

The normalized skew-centered physical weighted norm is exactly the norm of its selected-generation coefficient and gradient pullback.