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LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.LocalizationActualSplit

LocalizationActualSplit #

Ported from scottnarmstrong/Superdiffusion at 7f20476385d4af418f110303085ad0740c9eba46. Module imports, support namespace and local option directives adapted for Lean Pool.

Provider: X_z = S_z + tilde S_z and a generic pre-mesh intermediate toward the insertion step, #

at the actual carriers

Source displays in ABK26:

LocalizationSelection*.lean and LocalizationGluing*.lean prove all of this for abstract slope data, carrying caller propositions. LocalizationActualBackground.lean derives those propositions at the genuine P_z, bfF_z and correctors. This module composes the two: it selects the per-cell S_z and tilde S_z at the actual carriers, D the cell field as their sum, and feeds the resulting family into the gluing competitor bound and the cell algebra.

Why the sum is a definition and not a comparison #

The manuscript defines X_z by its own argmin display and then observes X_z = S_z + tilde S_z. Selecting X_z independently would make that observation an a.e. identity only, because the two argmins are unique only up to a null set. Below, the cell field is defined as the sum S_z + tilde S_z, so is literally true, and what is proved instead is that the sum satisfies the minimizer property (isDoubledMuMinimizerField. (localizationBackground.) (S R + T R)). What exists_localizationActualCellFields records as its uniqueness clauses is the a.e. uniqueness of S_z and of tilde S_z individually; the agreement of the defined sum with an independently selected X_z is NOT recorded as a theorem here — a caller wanting it must apply LocalizationSelectionExistence.sameAE_of_isDoubledMuMinimizerField to the sum's minimizer property itself.

What is proved #

Divergences from the printed statement #

One localization cell #

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.exists_localizationActualCellFields {d : ℕ} (sigma : Observable.PositiveScalar) (omega : Cutoff.ShellSeq d) (lowScale highScale : ℤ) (e e' : HCPolySupport.Vec d) {Q : HCPolySupport.TriadicCube d} (R : HCPolySupport.TriadicCube d) (hsub : HCPolySupport.openCubeSet R ⊆ HCPolySupport.openCubeSet Q) (aR : HCPolySupport.Book.Ch02.CoeffOn (HCPolySupport.Book.Ch02.cubeDomain R)) (wD : HCPolySupport.H10Function (HCPolySupport.openCubeSet Q)) {wN : HCPolySupport.H1MeanZeroFunction (HCPolySupport.openCubeSet Q)} (hwN : HCPolySupport.IsMeanZeroNeumannRhsWeakSolution (fun (x : HCPolySupport.Vec d) => 1) (HCPolySupport.openCubeSet Q) wN fun (x : HCPolySupport.Vec d) => -Corrector.streamForcing (↑sigma)⁻¹ omega lowScale highScale e' x) :

S_z, tilde S_z and X_z = S_z + tilde S_z on one localization cell.

At the actual carriers: R is the cell z + cu_n inside cu_K, P_z is e.Pz.def, bfF_z is e.Fz.def, and the background of the X_z display is localizationBackground. The conclusions are, in order:

  • T is a doubled response field, i.e. satisfies the Euler--Lagrange equation (first variation);
  • the Step-2 identity holds for T, proved from that first variation and not from mean-zeroness.

: on hwN, the defining property of w_{N,e'}^{(K)}, and on the inclusion hsub : openCubeSet R ⊆ openCubeSet Q (the cell sits inside the big cube; discharged by the descendant geometry at the call sites).

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.two_mul_doubledMuValue_localizationActual_add_eq {d : ℕ} (sigma : Observable.PositiveScalar) (omega : Cutoff.ShellSeq d) (lowScale highScale : ℤ) (e e' : HCPolySupport.Vec d) {Q : HCPolySupport.TriadicCube d} (R : HCPolySupport.TriadicCube d) (aR : HCPolySupport.Book.Ch02.CoeffOn (HCPolySupport.Book.Ch02.cubeDomain R)) (wD : HCPolySupport.H10Function (HCPolySupport.openCubeSet Q)) (wN : HCPolySupport.H1MeanZeroFunction (HCPolySupport.openCubeSet Q)) {S T : HCPolySupport.Book.Ch02.DoubledField d} (hS : HCPolySupport.Book.Ch02.IsDoubledMuMinimizer (HCPolySupport.Book.Ch02.cubeDomain R) aR (principalPz sigma omega lowScale highScale e e' R wD wN) S) (hT : HCPolySupport.Book.Ch02.IsDoubledResponseField (HCPolySupport.Book.Ch02.cubeDomain R) aR T) :

The second line of e.lower.bound.basic.split at the actual carriers. With S = S_z the constant-load minimizer at P_z and T = tilde S_z a doubled response field on the cell,

fint_R (S+T) . bfA (S+T)
  = P_z . bfA(R) P_z + 2 P_z . fint_R bfA (tilde S_z) + fint_R tilde S_z . bfA tilde S_z .

This is LocalizationBasicSplit.two_mul_doubledMuValue_add_eq with the load instantiated at e.Pz.def; the factor 2 is that module's normalization convention.: on the two binders hS, hT, both of which exists_localizationActualCellFields produces.

The whole descendant family #

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.exists_localizationActualCellSplit {d : ℕ} (sigma : Observable.PositiveScalar) (omega : Cutoff.ShellSeq d) (lowScale highScale : ℤ) (e e' : HCPolySupport.Vec d) {Q : HCPolySupport.TriadicCube d} (j : ℕ) (aCell : (R : HCPolySupport.TriadicCube d) → HCPolySupport.Book.Ch02.CoeffOn (HCPolySupport.Book.Ch02.cubeDomain R)) (wD : HCPolySupport.H10Function (HCPolySupport.openCubeSet Q)) {wN : HCPolySupport.H1MeanZeroFunction (HCPolySupport.openCubeSet Q)} (hwN : HCPolySupport.IsMeanZeroNeumannRhsWeakSolution (fun (x : HCPolySupport.Vec d) => 1) (HCPolySupport.openCubeSet Q) wN fun (x : HCPolySupport.Vec d) => -Corrector.streamForcing (↑sigma)⁻¹ omega lowScale highScale e' x) :

The per-cell split over the whole localization family.

S and T are the families z |-> S_z and z |-> tilde S_z, and the cell field is defined as fun R => S R + T R, so "Observe that X_z = S_z + tilde S_z" is literally true of it. Every conclusion is quantified over descendantsAtDepth Q j, the rendering of 3^n Z^d cap cu_K.

: on hwN, the defining property of w_{N,e'}^{(K)}.

The term consumer #

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.exists_localizationActualCellSplit_blockVecDot_coarseBlockMatrix_le {d : ℕ} (sigma : Observable.PositiveScalar) (omega : Cutoff.ShellSeq d) (lowScale highScale : ℤ) (e e' : HCPolySupport.Vec d) {Q : HCPolySupport.TriadicCube d} (j : ℕ) (a : HCPolySupport.Book.Ch02.CoeffOn (HCPolySupport.Book.Ch02.cubeDomain Q)) (aCell : (R : HCPolySupport.TriadicCube d) → HCPolySupport.Book.Ch02.CoeffOn (HCPolySupport.Book.Ch02.cubeDomain R)) (wD : HCPolySupport.H10Function (HCPolySupport.openCubeSet Q)) {wN : HCPolySupport.H1MeanZeroFunction (HCPolySupport.openCubeSet Q)} (hwN : HCPolySupport.IsMeanZeroNeumannRhsWeakSolution (fun (x : HCPolySupport.Vec d) => 1) (HCPolySupport.openCubeSet Q) wN fun (x : HCPolySupport.Vec d) => -Corrector.streamForcing (↑sigma)⁻¹ omega lowScale highScale e' x) :

A generic pre-mesh intermediate toward the insertion step and the first line of e.lower.bound.basic.split. This is NOT the manuscript's first insertion line: the printed line carries the mesh average over the scale-n grid and the actual cutoff coefficient bfA_m (the coefficientCutoffTriadicCoeffFamily.coeffOn instantiation) on the cube and on every cell; here the per-cell coefficient family aCell is abstract and the mesh average is not composed. Both are the successor module's mandate.

P . bfA_m(cu_K) P  <=  fint_{cu_K} X . bfA_m X ,
    X = sum_{z} (S_z + tilde S_z) 1_{z+cu_n} ,  P = bfAhom_{m-h}^{-1/2}(e'; e) .

Genuine ingredients: P is e.recurrence.P.def, the cell fields are the actual S_z + tilde S_z, and the background whose class they live in is the actual bfAhom_{m-h}^{-1/2}(e' + grad w_D; e + grad w_N + shom^{-1} h e'), whose membership in P + L^2_{pot,0}(cu_K) x Lsolo(cu_K) is derived by isDoubledMuAdmissible_localizationBackground and not assumed. NOT yet genuine: the coefficient family (abstract aCell, not the actual cutoff coefficients) and the mesh form (absent).

Per this direction, and only this direction, is available; the mesh average of the right-hand side is a separate lane's item.

: on hwN, the defining property of w_{N,e'}^{(K)}.