Documentation

LeanPool.CaffarelliKohnNirenberg.Foundation.Sobolev.WeakGradientGluingTBounds

Cellwise bounds for one measurable pressure gradient #

The slice bounds in paper/ckn.tex, Section sec:pressure, are transported from the derivative selected at a cell's scale to a fixed field. Spatial a.e. uniqueness preserves the complete quantitative majorant. Time windows are restricted only along an explicit subset inclusion.

A vector slice bound on an open cell transfers, coordinate by coordinate, to a fixed weak gradient on a larger spatial carrier and time set.

theorem CKN.Core.Step4.ae_glued_gradient_cell_bound_of_doubled_slice_bound {B : Set Foundation.Parabolic.Vec3} {I : Set ℝ} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {x : Foundation.Parabolic.Vec3} {t r : ℝ} (hr : 0 < r) {M : ℝ → ENNReal} (hball : Foundation.Parabolic.vec3Ball x r ⊆ B) (htime : Set.Ioc (t - r ^ 2) t ⊆ I) (hfield : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∀ (k : Fin 3), MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) k) B MeasureTheory.volume ∧ HasWeakPartialDerivOn B k (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => Dp (y, s) k) (hslice : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict (Set.Ioc (t - (2 * r) ^ 2) t), ∃ (D : Foundation.Parabolic.Vec3 → Foundation.Parabolic.Vec3), (∀ (k : Fin 3), MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => D y k) (euclideanBall x (2 * r / 2)) MeasureTheory.volume) ∧ MeasureTheory.MemLp D (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (euclideanBall x (2 * r / 2))) ∧ (∀ (k : Fin 3), HasWeakPartialDerivOn (euclideanBall x (2 * r / 2)) k (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => D y k) ∧ ∀ (k : Fin 3), MeasureTheory.eLpNorm (fun (y : Foundation.Parabolic.Vec3) => D y k) (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (euclideanBall x (2 * r / 2))) ≤ M s) :

The cell bound on a doubled cylinder supplies the bound on its half-radius spatial ball throughout the cell's shorter backward time window.

theorem CKN.Core.Step4.ae_glued_gradient_cell_data_of_doubled_slice_bound {B : Set Foundation.Parabolic.Vec3} {I : Set ℝ} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {x : Foundation.Parabolic.Vec3} {t r : ℝ} (hr : 0 < r) {M : ℝ → ENNReal} (hball : Foundation.Parabolic.vec3Ball x r ⊆ B) (htime : Set.Ioc (t - r ^ 2) t ⊆ I) (hfield : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∀ (k : Fin 3), MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) k) B MeasureTheory.volume ∧ HasWeakPartialDerivOn B k (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => Dp (y, s) k) (hslice : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict (Set.Ioc (t - (2 * r) ^ 2) t), ∃ (D : Foundation.Parabolic.Vec3 → Foundation.Parabolic.Vec3), (∀ (k : Fin 3), MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => D y k) (euclideanBall x (2 * r / 2)) MeasureTheory.volume) ∧ MeasureTheory.MemLp D (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (euclideanBall x (2 * r / 2))) ∧ (∀ (k : Fin 3), HasWeakPartialDerivOn (euclideanBall x (2 * r / 2)) k (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => D y k) ∧ ∀ (k : Fin 3), MeasureTheory.eLpNorm (fun (y : Foundation.Parabolic.Vec3) => D y k) (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (euclideanBall x (2 * r / 2))) ≤ M s) (k : Fin 3) :

The same field supplies the existential cell datum required by the cell-transfer theorem; the witness is its own restricted spatial slice.