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LeanPool.Superdiffusion.Algsuperdiff.Section4.Provider.ExcessDecay.OneStepOddClassCorner

OneStepOddClassCorner #

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

The corner pricing of the odd-class defect #

's residue (2). At two met faces the odd affine class collapses to {0} (affineLift_eq_zero_of_two_met), so the odd-class defect of the boundary producer degenerates to ‖V‖_{L²(U₂)} − E_raw(U₂,V) and the proved one-face pricing (★) does not apply. This module proves the corner pricing:

  ‖V‖_{L²(U₂)} ≤ C(d) · E_raw(U₂, V)                                (★★)

for V classically harmonic on the doubled window, odd under every met-face reflection, at a window meeting the upper faces of two distinct coordinates i ≠ j (the remaining met set arbitrary); and hence

  oddClassDefect x m n V 0 0 ≤ C(d) · E_raw(U₂, V) ,

the exact leg shape the proved K-package consumers carry at the corner datum (c, A) = (0, 0) — the only member of the collapsed class.

The mechanism #

Let ℓ* be an affine minimizer and f = V − ℓ*, E = ‖f‖_{L²(U₂)}, P = ‖ℓ*‖_{L²(U₂)}. With evenᵢ/evenⱼ the even parts of ℓ* at the two faces and e_{ij} the doubly even part (= evenⱼ of the affine evenᵢ),

  ℓ* = evenᵢ + evenⱼ − e_{ij} ,

and each of the three parts is priced on a window-hugging near-face slab by the two-point Taylor elimination (abs_evenAffinePart_le_pointwise_of_mem): the single-face applications at i and at j against the residual f, and the doubly even part at the face j against the residual V − evenᵢ on the corner slab, where the leftover normal ramp oddᵢ = ℓ* − evenᵢ is pointwise at most |Aᵢ|·delta and hence O(t)-small against P + ‖evenᵢ‖ by the box-moment lower bound. The Hessian remainders are O(t²)·‖f‖_{L²(R)}, and ‖f‖_{L²(R)} folds back to (E + P) by the full-met-set odd fold and the affine moment comparison. Choosing the depth fraction t = t(d) small absorbs every P-feedback at coefficient < 1, closing P ≤ C(d)·E.

Scope (disclosed) #

The two active faces are met upper faces, matching every proved convention of the one-face chain (evenAffinePart, the slab geometry, (★) itself are stated at upper faces). Lower and mixed corners require either the mechanical lower-face twins of those atoms or a coordinate-negation transport; neither is built here, and the composed corner consumption must supply the upper-upper configuration or its transported image. The met-face oddness binders are the global pointwise identities, exactly as in the proved (★) and one-face producer.

1. The slab estimate, box-generic #

theorem Algsuperdiff.Section4.Provider.ExcessDecay.Schauder.normalizedL2On_evenAffinePart_slab_le {d : ℕ} {m : ℤ} {x : HCPolySupport.Vec d} {face : Fin d} {V : HCPolySupport.Vec d → ℝ} (hVodd : ∀ (z : HCPolySupport.Vec d), V (HCPolySupport.coordFaceReflection (1 / 2 * 3 ^ m) face z) = -V z) {c' : ℝ} {A' : HCPolySupport.Vec d} {delta M : ℝ} (hdelta : 0 < delta) (hM : 0 ≤ M) {loP hiP loT hiT : Fin d → ℝ} (hPpos : 0 < (MeasureTheory.volume (coordBox loP hiP)).toReal) (hharmT : ∀ z ∈ coordBox loT hiT, InnerProductSpace.HarmonicAt ((fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) ∘ ⇑toEuc.symm) (toEuc z)) (hMT : ∀ z ∈ coordBox loT hiT, ‖fderiv ℝ (fderiv ℝ ((fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) ∘ ⇑toEuc.symm)) (toEuc z)‖ ≤ M) (hPT : coordBox loP hiP ⊆ coordBox loT hiT) (hrT : ∀ y ∈ coordBox loP hiP, HCPolySupport.coordFaceReflection (1 / 2 * 3 ^ m) face y ∈ coordBox loT hiT) (hpT : ∀ y ∈ coordBox loP hiP, y - delta • HCPolySupport.basisVec face ∈ coordBox loT hiT) (hdepth : ∀ y ∈ coordBox loP hiP, 1 / 2 * 3 ^ m - delta < y face ∧ y face < 1 / 2 * 3 ^ m) (hfP : MeasureTheory.MemLp (fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) 2 (MeasureTheory.volume.restrict (coordBox loP hiP))) (hfD : MeasureTheory.MemLp (fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) 2 (MeasureTheory.volume.restrict (coordBox (fun (l : Fin d) => loP l - (delta • HCPolySupport.basisVec face) l) fun (l : Fin d) => hiP l - (delta • HCPolySupport.basisVec face) l))) :
Support.normalizedL2On (coordBox loP hiP) (evenAffinePart x m face c' A') ≤ ((2 * Support.normalizedL2On (coordBox loP hiP) fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) + Support.normalizedL2On (coordBox (fun (l : Fin d) => loP l - (delta • HCPolySupport.basisVec face) l) fun (l : Fin d) => hiP l - (delta • HCPolySupport.basisVec face) l) fun (y : HCPolySupport.Vec d) => V y - Support.affineEval (c' - HCPolySupport.vecDot A' x) A' y) + 3 * (M * delta ^ 2)

The near-face slab estimate, box-generic: the L² size of the even part on the slab is priced by the residual on the slab, on its inward translate, and the Hessian remainder.

2. Transfer helpers #

The subset transfer with an explicit ratio bound.

theorem Algsuperdiff.Section4.Provider.ExcessDecay.Schauder.ratio_le_inv_t_pow {d : ℕ} {a b A w tt delta : ℝ} (ha0 : 0 ≤ a) (haA : a ≤ w ^ d) (hb : delta ^ d ≤ b) (hw : 0 < w) (htt : 0 < tt) (hdel : delta = tt * w) (hab : a = A) :
A / b ≤ (1 / tt) ^ d

The volume-ratio bound |U|/|B| ≤ (1/t)^d for a slab of edge ≥ delta.

3. The Hessian value on a Taylor set #

theorem Algsuperdiff.Section4.Provider.ExcessDecay.Schauder.exists_hessian_value {d : ℕ} {m k : ℤ} {x : HCPolySupport.Vec d} (hx : x ∈ HCPolySupport.openCubeSet (HCPolySupport.originCube d m)) (hkm : k < m) {tt delta : ℝ} (htt0 : 0 < tt) (hdel : delta = tt * 3 ^ k) {Tbox : Set (HCPolySupport.Vec d)} (hballs : ∀ z ∈ Tbox, Metric.ball z (3 ^ k / 16) ⊆ reflectedWindow x m k) {F : HCPolySupport.Vec d → ℝ} (hFR : MeasureTheory.MemLp F 2 (MeasureTheory.volume.restrict (reflectedWindow x m k))) (hFharm : InnerProductSpace.HarmonicOnNhd (F ∘ ⇑toEuc.symm) (⇑toEuc '' reflectedWindow x m k)) {CH : ℝ} (hCH0 : 0 ≤ CH) (hCH : ∀ (W : Set (HCPolySupport.Vec d)) (V : HCPolySupport.Vec d → ℝ) (p : HCPolySupport.Vec d) (r : ℝ), MeasureTheory.volume W ≠ ⊤ → 0 < (MeasureTheory.volume W).toReal → InnerProductSpace.HarmonicOnNhd (V ∘ ⇑toEuc.symm) (⇑toEuc '' W) → MeasureTheory.IntegrableOn (fun (y : HCPolySupport.Vec d) => V y ^ 2) W MeasureTheory.volume → 0 < r → Metric.ball p r ⊆ W → ‖fderiv ℝ (fderiv ℝ (V ∘ ⇑toEuc.symm)) (toEuc p)‖ ≤ CH * r⁻¹ * r⁻¹ * √((MeasureTheory.volume W).toReal / r ^ d) * Support.normalizedL2On W V) :
∃ (M : ℝ), 0 ≤ M ∧ (∀ z ∈ Tbox, ‖fderiv ℝ (fderiv ℝ (F ∘ ⇑toEuc.symm)) (toEuc z)‖ ≤ M) ∧ M * delta ^ 2 ≤ CH * 256 * √(32 ^ d) * tt ^ 2 * Support.normalizedL2On (reflectedWindow x m k) F

The Hessian value. For F harmonic on the doubled window and a set whose points carry sup-balls of radius 3^k/16 inside it, there is a Hessian bound M on the set with M·delta² ≤·256·√(32^d)·t²·‖F‖_{L²(R)} at delta = t·3^k.

4. Small instantiation helpers #

theorem Algsuperdiff.Section4.Provider.ExcessDecay.Schauder.moment_transfer_window_le {d : ℕ} {x : HCPolySupport.Vec d} {m k : ℤ} (hx : x ∈ HCPolySupport.openCubeSet (HCPolySupport.originCube d m)) (hkm : k < m) {loP hiP : Fin d → ℝ} (hltP : ∀ (l : Fin d), loP l < hiP l) {c' : ℝ} {g' : HCPolySupport.Vec d} (hcases : ∀ (l : Fin d), g' l = 0 ∨ loP l = hugLo x m k l ∧ hiP l = hugHi x m k l) :

The controlled comparison of the window against a window-hugging slab: κ = 4, active coordinates carried by zero slopes.