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LeanPool.Superdiffusion.Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.Closure.GammaTenInteriorFamily

GammaTenInteriorFamily #

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

The Besov envelope of Step 2 on an arbitrary sub-mesh #

ABK26, Step 2 of l.approximate.recurrence.formula, e.lower.bound.oscillations.

Why the proved grid device is not enough #

The envelope device of Closure.GammaTenEnvelopeInputGrid is set up on the full mesh descendantsAtDepth Q j, so its per-depth input D i is the full-mesh grid fourth moment of the oscillation cells at depth i. The depth-indexed endpoints of Closure.GammaTenDepthOscillation are stated on the interior mesh interiorMesoCubeGrid d K (nmesh - i) (m - h - 1), the carrier, and --- as that module records --- the boundary-strip transfer of LocalizationOscillationFullMesh does not survive the depth index: the missing fraction d 3^{(m-h)-K} is the same at every depth, while the Besov tower's own weights 2^{i+1} 3^{4 s i} grow geometrically, so a depth-independent remainder is not summable.

This module removes that obstruction by running the same envelope device on an arbitrary sub-family I of the mesh. Nothing analytic changes: the proved exists_grid_pathwise_envelope_of_monotone is already stated at an arbitrary Finset (TriadicCube d); what has to be redone is only the fold, because the proved fold identifies avsum_{R in mesh} avsum_{R' in desc(R,i)} with the refined mesh average through descendantsAverage_add_eq_descendantsAverage_descendantsAverage, an identity that holds for the full mesh only.

The replacement is the finite combinatorics of this module: the depth-i descendant families of distinct cells of a common mesh are disjoint (disjoint_descendantsAtDepth_of_ne), so for a nonnegative cell functional the sub-family's iterated sum is dominated by any grid T containing all those descendants (sum_descendantsAtDepth_le_of_subset), at the explicit cardinality cost |T| / (|I| 3^{d i}) (cubeFamilyAverage_descendantsAverage_le). On the interior mesh that cost is 1 / (1 - boundary fraction), i.e. below 2 under the recurrence's own large-cube gate, and it is carried in the statement.

What is proved #

Binders #

Measurability and fourth-power integrability of the oscillation cells at the descendants of the sub-family's cells, the L^2 membership of the field there, the common scale of the sub-family and the per-depth bounds. No smallness gate, no geometry beyond the triadic mesh, and nothing about the corrector or the coefficient field occurs.

Scope #

Internal Provider infrastructure for the Step-2 fluctuation estimate. There is no sorry, no admit, no custom axiom and no set_option maxHeartbeats.

References #

Disjointness of the descendant families of a common mesh #

Distinct cells of a common mesh have disjoint descendant families. Two distinct cells of descendantsAtDepth Q j have disjoint open cubes, and a cube is contained in the open cube of each of its ancestors, so a common descendant would have empty open cube. Unconditional.

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.Closure.sum_descendantsAtDepth_le_of_subset {d : ℕ} {Q : HCPolySupport.TriadicCube d} {j : ℕ} {I T : Finset (HCPolySupport.TriadicCube d)} (hI : I ⊆ HCPolySupport.descendantsAtDepth Q j) {i : ℕ} (hsub : ∀ R ∈ I, HCPolySupport.descendantsAtDepth R i ⊆ T) (f : HCPolySupport.TriadicCube d → ℝ) (hf : ∀ R' ∈ T, 0 ≤ f R') :
∑ R ∈ I, ∑ R' ∈ HCPolySupport.descendantsAtDepth R i, f R' ≤ ∑ R' ∈ T, f R'

The iterated sum over a sub-mesh is below the sum over any grid containing the descendants. Unconditional for a family nonnegative on that grid.

The sub-mesh depth average, against a containing grid.

If every depth-i descendant family of the sub-mesh I proves inside the grid T, and f is nonnegative on T, then the sub-mesh average of the depth-i descendant averages is below rho times the T-average, rho being any bound for the cardinality ratio |T| / (|I| 3^{d i}).

Unconditional finite combinatorics.

The fold at an arbitrary sub-mesh #

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.Closure.cubeFamilyAverage_integral_pow_four_oscMajorant_le_family {d : ℕ} {Omega : Type u_1} [MeasurableSpace Omega] (mu : MeasureTheory.Measure Omega) (I : Finset (HCPolySupport.TriadicCube d)) (nbase : ℤ) (s : ℝ) (N : ℕ) (U : Omega → HCPolySupport.Vec d → HCPolySupport.Vec d) (hint : ∀ i ∈ Finset.range (N + 1), ∀ R ∈ I, ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, MeasureTheory.Integrable (fun (w : Omega) => meshOscillationCell (nbase - ↑i) (U w) R' ^ 4) mu) (D : ℕ → ℝ) (hD : ∀ i ∈ Finset.range (N + 1), (cubeFamilyAverage I fun (R : HCPolySupport.TriadicCube d) => HCPolySupport.descendantsAverage R i fun (R' : HCPolySupport.TriadicCube d) => ∫ (w : Omega), meshOscillationCell (nbase - ↑i) (U w) R' ^ 4 ∂mu) ≤ D i) :
(cubeFamilyAverage I fun (R : HCPolySupport.TriadicCube d) => ∫ (w : Omega), oscMajorant nbase s N (U w) R ^ 4 ∂mu) ≤ ∑ i ∈ Finset.range (N + 1), 2 ^ (i + 1) * Real.rpow 3 (s * ↑i) ^ 4 * D i

The grid fourth moment of the majorant, folded over depths, at an arbitrary sub-mesh.

The fold of Closure.GammaTenEnvelopeInputGrid.oscMajorant whose per-depth input D i is read at the sub-mesh I itself rather than at the full mesh. The proof is the full-mesh one with the closing identity descendantsAverage_add_eq_descendantsAverage_descendantsAverage --- which is available only on the full mesh --- replaced by the hypothesis hD.

on hint, the standing fourth-power integrability of the oscillation cells at the descendants of the sub-mesh, and on the per-depth bounds hD.

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.Closure.integrable_pow_four_oscMajorant_family {d : ℕ} {Omega : Type u_1} [MeasurableSpace Omega] (mu : MeasureTheory.Measure Omega) (nbase : ℤ) (s : ℝ) (N : ℕ) (U : Omega → HCPolySupport.Vec d → HCPolySupport.Vec d) (R : HCPolySupport.TriadicCube d) (hmeascell : ∀ (i : ℕ), ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, Measurable fun (w : Omega) => meshOscillationCell (nbase - ↑i) (U w) R') (hintcell : ∀ (i : ℕ), ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, MeasureTheory.Integrable (fun (w : Omega) => meshOscillationCell (nbase - ↑i) (U w) R' ^ 4) mu) :
MeasureTheory.Integrable (fun (w : Omega) => oscMajorant nbase s N (U w) R ^ 4) mu

The fourth power of the majorant is integrable at every cell of the sub-mesh, by domination through the fold.

on the measurability and the fourth-power integrability of the oscillation cells at the descendants of that cell.

The composite #

theorem Algsuperdiff.Section3.Provider.Diffusivity.ApproximateRecurrence.Closure.exists_besovEnvelope_of_family_depth_oscillation {d : ℕ} {Omega : Type u_1} [MeasurableSpace Omega] (mu : MeasureTheory.Measure Omega) (I : Finset (HCPolySupport.TriadicCube d)) (nbase : ℤ) (s : ℝ) (U : Omega → HCPolySupport.Vec d → HCPolySupport.Vec d) (hscale : ∀ R ∈ I, R.scale = nbase) (hmeascell : ∀ (i : ℕ), ∀ R ∈ I, ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, Measurable fun (w : Omega) => meshOscillationCell (nbase - ↑i) (U w) R') (hintcell : ∀ (i : ℕ), ∀ R ∈ I, ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, MeasureTheory.Integrable (fun (w : Omega) => meshOscillationCell (nbase - ↑i) (U w) R' ^ 4) mu) (hmem2 : ∀ (w : Omega) (i : ℕ), ∀ R ∈ I, ∀ R' ∈ HCPolySupport.descendantsAtDepth R i, MeasureTheory.MemLp (U w) 2 (HCPolySupport.normalizedCubeMeasure R')) (D : ℕ → ℝ) (hD : ∀ (i : ℕ), (cubeFamilyAverage I fun (R : HCPolySupport.TriadicCube d) => HCPolySupport.descendantsAverage R i fun (R' : HCPolySupport.TriadicCube d) => ∫ (w : Omega), meshOscillationCell (nbase - ↑i) (U w) R' ^ 4 ∂mu) ≤ D i) {C : ℝ} (hC : 0 ≤ C) (hsum : ∀ (N : ℕ), ∑ i ∈ Finset.range (N + 1), 2 ^ (i + 1) * Real.rpow 3 (s * ↑i) ^ 4 * D i ≤ C) :
∃ (B : HCPolySupport.TriadicCube d → Omega → ℝ), (∀ (R : HCPolySupport.TriadicCube d) (w : Omega), 0 ≤ B R w) ∧ (∀ R ∈ I, MeasureTheory.MemLp (B R) 4 mu) ∧ (cubeFamilyAverage I fun (R : HCPolySupport.TriadicCube d) => ∫ (w : Omega), B R w ^ 4 ∂mu) ≤ C ∧ ∀ R ∈ I, ∀ᵐ (w : Omega) ∂mu, ∀ (N : ℕ), HCPolySupport.cubeBesovPositiveVectorPartialSeminormTwo R s N (U w) ≤ B R w

The Besov envelope of Step 2 on an arbitrary sub-mesh, from per-depth sub-mesh oscillation moments alone.

The envelope device of Closure.GammaTenEnvelopeInputGrid, run at an arbitrary family I of cells of a common scale nbase. The conclusion is the exact shape Closure.ClosureInteriorSplit.ClosureInteriorBesovEnvelopeInput consumes.

on hscale, hmeascell, hintcell, hmem2, hD and hsum.