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LeanPool.Superdiffusion.Algsuperdiff.Section4.Provider.Proportion.TranslatedLocality

TranslatedLocality #

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

Translated-cube locality of the multiscale-ellipticity literal #

ABK26, §4.1, l.good.scales.ratio.lambda, the two-dependence step: the per-scale atoms 𝒴_n are asserted to be 2-dependent. The independence producer consumes that assertion as locality: 𝒴_n must be measurable for the integral-local information Cutoff.cutoffSampleLocalSigma M (n−2) (annulusRegion d n) of the annulus it reads. This module supplies that locality, unconditionally.

The bridge #

The 𝒢₀ atom is written by translating the sample, never the cube:

λ_{γ,2}^{-1}(z+□_j; a_c)  :=  cutoffLowerEllipticityInvLiteral M j c γ 2
                                 (translateCutoffSample z ω) ,

while the proved locality statement BadEvents.measurable_cubeLowerEllipticityInvLiteral_cutoffSampleLocal is about the cube reading cubeLowerEllipticityInvLiteral M Q c γ 2 ω at a genuine TriadicCube Q. The two are identified by the proved pathwise swap BadEvents.cubeLowerEllipticityInvLiteral_translateCutoffSample, whose mathematical content is the Chapter 2 translation covariance BadEvents.lambdaSq_cutoff_translateCutoffSample of the actual coefficient cutoff.

The decisive point is that the centres occurring in §4.1 are triadic lattice points z = 3^j v, so z + □_j is the triadic cube ⟨j, v⟩ (Localize.latticeCube, whose triadicCubeShift is Support.triadicLatticePoint). No σ-algebra on a translated region, and no translated-region bookkeeping, is needed: the cube reading is available at the honest cube, and the locality lemma applies to it verbatim. Arbitrary real translates z are not covered and are not needed anywhere in §4.1.

The chain #

  1. cubeSet_latticeCube_subset_annulusRegion — the geometry: a lattice cube 3^j v + □_j whose centre lies in the open annulus □_n ∖ □_{n−1} has its whole (half-open) realization inside annulusRegion d n, for j ≤ n−1. This is the proved no-enlargement fact Probability.mem_annulusRegion_of_le_triadicLatticePoint, read at the cube.
  2. cutoffLowerEllipticityInvLiteral_translateCutoffSample_latticeCube — the core identity, in the orientation the Section 4 carriers need.
  3. measurable_cutoffLowerEllipticityInvLiteral_translate_cutoffSampleLocal — the general export: the translated-sample reading of the λ-literal at the lattice cube ⟨j, v⟩, at cutoff level c, is cutoffSampleLocalSigma M m U-measurable for every U ⊇ cubeSet ⟨j, v⟩ and every m ≥ c. The domain scale j and the cutoff scale c are independent parameters, so the 𝒢₂ reading z + □_n at a_{n−2} is covered as well.
  4. measurable_cgExcess_annulusRegion_local and measurable_Ycal_annulusRegion_local — the 𝒢₀ instances, ending at the hloc slot of columnsIndep_Ycal.

The corrected reduction (recorded) #

Reducing the 𝒴-locality to a per-cube slot quantified over every index vector v : Fin d → ℤ gives a slot that is not dischargeable, and not because of a missing lemma: a cube 3^{k−2}v + □_{k−2} with v outside the annulus enumeration is genuinely not read by annulusRegion d n. The 0-floored maximum only ever evaluates the bracket on latticeAnnulusFinset d (k−2) n (n−1), so the honest reduction quantifies over the members of that Finset; that is measurable_Ycal_local_of_annulusFinset below, on top of the restricted measurable_fmax_of_mem. The endpoint delivered is unconditional.

Scope #

Provider material: proved local helpers. Every statement is pointwise in the sample; nothing is a.e. and no hypothesis is added to any consumer.

References #

1. The geometry: a lattice cube of the annulus stays in the annulus #

The read cube sits inside the annulus region. If the lattice point 3^j v lies in the open triadic annulus □_n ∖ □_{n−1} and j ≤ n − 1, then the entire half-open realization of the triadic cube ⟨j, v⟩ = 3^j v + □_j is contained in annulusRegion d n.

This is the cube-level reading of the proved no-enlargement fact Probability.mem_annulusRegion_of_le_triadicLatticePoint: the cubes read by the per-scale atom tile the annulus and do not stick out of it, so no fattening of the observation region — and hence no degradation of the separation count — is incurred.

2. The core identity at a triadic lattice point #

The translated-sample reading is the translated-cube reading.

λ_{s,q}^{-1}(□_j; a_c(τ_{3^j v} ω))  =  λ_{s,q}^{-1}(3^j v + □_j; a_c(ω)) ,

i.e. the λ-functional of the translated field on the centred cube equals the functional of the field on the translated cube. This is the proved pathwise swap BadEvents.cubeLowerEllipticityInvLiteral_translateCutoffSample read at the lattice cube ⟨j, v⟩, whose base point is Support.triadicLatticePoint j v and whose scale is j; its own content is the Chapter 2 translation covariance of the actual coefficient cutoff. It holds at every sample point, for every cutoff level c and every admissible exponent, with no hypothesis.

3. The general locality export #

The λ-literal read at a translated cube is integral-local.

For a triadic lattice centre z = 3^j v, an observation region U containing the closed cube z + □_j, and any shell index m at or above the cutoff level c, the translated-sample reading

ω ↦ λ_{s,q}^{-1}(z + □_j; a_c(ω))  =  (cutoffLowerEllipticityInvLiteral M j c s q)
                                          (translateCutoffSample z ω)

is Cutoff.cutoffSampleLocalSigma M m U-measurable.

Nothing is a.e.: the literal is the genuinely measurable observable, and the locality is the proved BadEvents.measurable_cubeLowerEllipticityInvLiteral_cutoffSampleLocal, whose descendant tree never leaves the closed cube. The domain scale j and the cutoff level c are independent, so this covers the 𝒢₀ reading (j = c) and the 𝒢₂-style reading (c = j − 2) alike.

4. The 𝒢₀ bracket at an annulus centre #

The 𝒢₀ bracket at a lattice centre of the annulus is local. For a centre enumerated by Support.latticeAnnulusSet d j n (n−1) with j ≤ n − 2, the excess 𝒳_j(3^j v) is measurable for the integral-local information of annulusRegion d n at shell index n − 2.

The scale hypothesis j ≤ n − 2 is exactly what the 𝒢₀ lane supplies (j = k − 2 with k ≤ n): it gives both the geometric room j ≤ n − 1 and the shell-index comparison the local σ-field needs.

5. The annulus maximum #

theorem Algsuperdiff.Section4.Provider.Proportion.measurable_fmax_of_mem {Omega : Type u_1} {iota : Type u_2} [MeasurableSpace Omega] (S : Finset iota) {f : iota → Omega → ℝ} (hf : ∀ i ∈ S, Measurable (f i)) :
Measurable fun (omega : Omega) => fmax S fun (i : iota) => f i omega

Measurability of the 0-floored maximum from the members alone. The proved measurable_fmax asks for measurability of every index; the maximum only ever evaluates the members of S, and that is all the §4.1 lattice maxima can supply (a centre outside the annulus enumeration reads a cube the annulus does not contain).

6. The 𝒴-locality: the hloc slot of the concentration lane #

theorem Algsuperdiff.Section4.Provider.Proportion.measurable_Ycal_local_of_annulusFinset {d : ℕ} (M : Section3.ABKModel d) (Ccg sprime : ℝ) (n : ℤ) (hatomloc : ∀ k ≤ n, ∀ v ∈ latticeAnnulusFinset d (k - 2) n (n - 1), Measurable fun (omega : Section3.Cutoff.CutoffSample d) => Localize.cgExcess M Ccg (k - 2) (Support.triadicLatticePoint (k - 2) v) omega) :
Measurable (Ycal M Ccg sprime n)

The corrected per-cube reduction. 𝒴_n is local as soon as the 𝒢₀ bracket is local at each centre the annulus maxima actually enumerate. The quantifier ranges over the members of latticeAnnulusFinset d (k−2) n (n−1), which is what the 0-floored maximum reads; quantifying over all v : Fin d → ℤ asks for locality at cubes the annulus does not contain, and is not dischargeable.

𝒴_n is local — unconditionally. This is the hloc slot of columnsIndep_Ycal: the 𝒢₀ score field at index n is measurable for the integral-local information cutoffSampleLocalSigma M (n−2) (annulusRegion d n) of the annulus it reads.

Together with Probability.separatedBy_annulusRegion_of_gap this is the honest content's one-line 2-dependence assertion: the atoms are measurable for regions that are separated at the shared-shell threshold, which is exactly what iIndepFun_of_local_cutoffSample consumes.