Coarse-graining support: Support.Sobolev.Foundations.CubeCalderonZygmund.GoodLambdaVitaliSum #
Imported from the Apache-2.0 CoarseGraining development at commit
c7ddd76c08ade64fed1b8d2ca51be14dfee8deb4.
Measure summation after Vitali selection #
This file isolates the purely measure-theoretic summation step used after a Vitali selection of stopping balls. It deliberately knows nothing about the origin of the high-level set or the control measure.
theorem
HCPolySupport.CubeCalderonZygmund.measure_le_mul_measure_of_vitali_closedBall_cover
{d : ℕ}
{ι : Type u_1}
(ν κ : MeasureTheory.Measure (Vec d))
(target ambient : Set (Vec d))
(u : Set ι)
(centre : ι → Vec d)
(radius : ι → ℝ)
(τ : ℝ)
(K : ENNReal)
(hpositive : ∀ i ∈ u, 0 < radius i)
(hdisjoint : u.PairwiseDisjoint fun (i : ι) => Metric.closedBall (centre i) (radius i))
(hcover : target ⊆ ⋃ i ∈ u, Metric.closedBall (centre i) (τ * radius i))
(hlocal :
∀ i ∈ u, ν (target ∩ Metric.closedBall (centre i) (τ * radius i)) ≤ K * κ (Metric.closedBall (centre i) (radius i)))
(hambient : ⋃ i ∈ u, Metric.closedBall (centre i) (radius i) ⊆ ambient)
:
Sum local estimates over a Vitali-selected family. The selected original
balls are pairwise disjoint and have positive radius, hence are countable in
the separable space Vec d; their enlarged balls only provide the cover and
need not be disjoint.