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LeanPool.CaffarelliKohnNirenberg.Core.Step4.PressureGradientOriginClauseDoubling

Doubled source cylinders for clipped origin cells #

The pressure slice estimate on a cylinder of radius 2 * r controls its half-ball of radius r. Weak derivative uniqueness on the intersection with the origin carrier transfers that bound to a field defined only on the carrier ball. The resulting time integral uses the clipped cell window. For centres in the closed origin cylinder, this construction is admissible through radius (1 - R₁) / 2, twice the origin margin scale.

Carrier cell bounds from slicewise bounds on the pressure #

The one-sided estimate of prop:bootstrap sees the selected pressure gradient only through the indicator of the backward carrier parabolicCylinder 0 0 R₁. A cell bound for that indicator is a bound for the integral of the gradient over the intersection of the cell with the carrier, and by the product decomposition of that intersection the integral splits into a time integral of spatial slice integrals whose times all lie in (-R₁ ^ 2, 0].

This module turns a multiscale slicewise L^{6/5} majorant for the weak gradients of the pressure slices into exactly those carrier cell bounds. The majorant is measured on the intersection vec3Ball x r ∩ vec3Ball 0 R₁ of the cell ball with the carrier ball, and its two time integrals are taken over the clipped windows. Nothing here refers to the gradient at a time outside the time factor of the unit cylinder.

theorem CKN.Core.Step4.originClauseCarrierCellIntegral_le_of_slice_bounds {I : Set ℝ} {R₀ R₁ : ℝ} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {M : ℝ → ENNReal} {Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {i : Fin 3} {x : Foundation.Parabolic.Vec3} {t r : ℝ} (hR₁ : 0 ≤ R₁) (hR₁one : R₁ ≤ 1) (hI : Set.Icc (-1) 0 ⊆ I) (hDmeas : AEMeasurable (fun (z : Foundation.Parabolic.ParabolicPoint) => Dp z i) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁ ×ˢ I))) (hid : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∀ (g : Foundation.Parabolic.Vec3 → ℝ), MeasureTheory.LocallyIntegrableOn g (Foundation.Parabolic.vec3Ball 0 R₀) MeasureTheory.volume → HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₀) i (fun (y : Vec 3) => p (y, s)) g → (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) i) =ᵐ[MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁)] g) (hslice : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∃ (g : Foundation.Parabolic.Vec3 → ℝ), MeasureTheory.LocallyIntegrableOn g (Foundation.Parabolic.vec3Ball 0 R₀) MeasureTheory.volume ∧ HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₀) i (fun (y : Vec 3) => p (y, s)) g ∧ MeasureTheory.eLpNorm g (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball x r ∩ Foundation.Parabolic.vec3Ball 0 R₁)) ≤ M s) :

The integral of a gradient component over the part of a cell that meets the backward carrier is bounded by the clipped time integral of a slicewise L^{6/5} majorant. Only the times in (-R₁ ^ 2, 0], which the domain hypothesis of thm:A places inside the solution interval, are used.

theorem CKN.Core.Step4.originClauseCellBounds_of_multiscale_majorant {I : Set ℝ} {R₀ R₁ θ : ℝ} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {A B : ENNReal} {M : Fin 3 → Foundation.Parabolic.Vec3 → ℝ → ℝ → ENNReal} (hR₁ : 0 ≤ R₁) (hR₁one : R₁ ≤ 1) (hI : Set.Icc (-1) 0 ⊆ I) (hslice : ∀ (i : Fin 3) (x : Foundation.Parabolic.Vec3) (r : ℝ), ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∃ (g : Foundation.Parabolic.Vec3 → ℝ), MeasureTheory.LocallyIntegrableOn g (Foundation.Parabolic.vec3Ball 0 R₀) MeasureTheory.volume ∧ HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₀) i (fun (y : Vec 3) => p (y, s)) g ∧ MeasureTheory.eLpNorm g (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball x r ∩ Foundation.Parabolic.vec3Ball 0 R₁)) ≤ M i x r s) (hgrowth : ∀ (i : Fin 3), ∀ z ∈ Foundation.Parabolic.parabolicCylinder 0 0 (3 / 4), ∀ (r : ℝ), 0 < r → r ≤ R₁ → ∫⁻ (s : ℝ) in Set.Ioc (z.2 - r ^ 2) z.2 ∩ Set.Ioc (-R₁ ^ 2) 0, M i z.1 r s ^ (6 / 5) ≤ A * ENNReal.ofReal (r ^ θ)) (hglobal : ∀ (i : Fin 3), ∫⁻ (s : ℝ) in Set.Ioc (-R₁ ^ 2) 0, M i 0 R₁ s ^ (6 / 5) ≤ B) (Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3) (hDmeas : ∀ (i : Fin 3), AEMeasurable (fun (z : Foundation.Parabolic.ParabolicPoint) => Dp z i) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁ ×ˢ I))) (hid : ∀ (i : Fin 3), ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, ∀ (g : Foundation.Parabolic.Vec3 → ℝ), MeasureTheory.LocallyIntegrableOn g (Foundation.Parabolic.vec3Ball 0 R₀) MeasureTheory.volume → HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₀) i (fun (y : Vec 3) => p (y, s)) g → (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) i) =ᵐ[MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁)] g) :

The two carrier integral constants of the one-sided Morrey transfer, from a multiscale slicewise majorant with clipped time windows. The majorant M i x r s bounds the L^{6/5} norm of the slice weak gradient on the intersection of the cell ball with the carrier ball; hgrowth and hglobal record the two clipped time integrals it has to satisfy. Every cell scale is used, which a single-scale slicewise bound cannot replace.

The doubled-radius slice bound transfers to a weak gradient on the carrier ball by uniqueness on the intersection of the two spatial balls.

theorem CKN.Core.Step4.originClauseCarrierCellIntegral_le_of_double_radius {I : Set ℝ} {R₁ : ℝ} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {i : Fin 3} {x : Foundation.Parabolic.Vec3} {t r : ℝ} {N : ℝ → ENNReal} (hR₁ : 0 ≤ R₁) (hR₁one : R₁ ≤ 1) (hI : Set.Icc (-1) 0 ⊆ I) (hr : 0 < r) (hDmeas : AEMeasurable (fun (z : Foundation.Parabolic.ParabolicPoint) => Dp z i) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁ ×ˢ I))) (hfield : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) i) (Foundation.Parabolic.vec3Ball 0 R₁) MeasureTheory.volume ∧ HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₁) i (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => Dp (y, s) i) (hslice : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict (Set.Ioc (t - (2 * r) ^ 2) t), ∃ (g : Foundation.Parabolic.Vec3 → ℝ), MeasureTheory.LocallyIntegrableOn g (euclideanBall x (2 * r / 2)) MeasureTheory.volume ∧ HasWeakPartialDerivOn (euclideanBall x (2 * r / 2)) i (fun (y : Vec 3) => p (y, s)) g ∧ MeasureTheory.eLpNorm g (ENNReal.ofReal (6 / 5)) (MeasureTheory.volume.restrict (euclideanBall x (2 * r / 2))) ≤ N s) :

The carrier-cell integral consumer applied to the actual norm of the fixed field, followed by its doubled-radius bound on the clipped time window.

theorem CKN.Core.Step4.originClause_doubleRadius_subset_unit {R₁ r : ℝ} {z : Foundation.Parabolic.ParabolicPoint} (hR₁ : 0 < R₁) (hR₁one : R₁ < 1) (hr : 0 < r) (hmargin : r ≤ (1 - R₁) / 2) (hz : z ∈ closure (Foundation.Parabolic.parabolicCylinder 0 0 R₁)) :

Centres in the closed origin cylinder admit doubled source cylinders through twice the margin scale, including the endpoint radius.

theorem CKN.Core.Step4.originClauseCarrierCellIntegral_le_of_sws {Ω : Set Foundation.Parabolic.Vec3} {I : Set ℝ} {q R₁ : ℝ} {u : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {Du : Foundation.Parabolic.ParabolicPoint → Fin 3 → Foundation.Parabolic.Vec3} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {f : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} (hsol : IsSuitableWeakSolutionIntegrable Ω I q u Du p f) (hdom : closure (Foundation.Parabolic.parabolicCylinder 0 0 1) ⊆ spaceTimeSet Ω I) (hR₁ : 0 < R₁) (hR₁one : R₁ < 1) {Dp : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {i : Fin 3} (hDmeas : AEMeasurable (fun (z : Foundation.Parabolic.ParabolicPoint) => Dp z i) (MeasureTheory.volume.restrict (Foundation.Parabolic.vec3Ball 0 R₁ ×ˢ I))) (hfield : ∀ᵐ (s : ℝ) ∂MeasureTheory.volume.restrict I, MeasureTheory.LocallyIntegrableOn (fun (y : Foundation.Parabolic.Vec3) => Dp (y, s) i) (Foundation.Parabolic.vec3Ball 0 R₁) MeasureTheory.volume ∧ HasWeakPartialDerivOn (Foundation.Parabolic.vec3Ball 0 R₁) i (fun (y : Vec 3) => p (y, s)) fun (y : Vec 3) => Dp (y, s) i) {z : Foundation.Parabolic.ParabolicPoint} {r : ℝ} (hr : 0 < r) (hmargin : r ≤ 2 * ((1 - R₁) / 4)) (hz : z ∈ closure (Foundation.Parabolic.parabolicCylinder 0 0 R₁)) :

Suitability supplies the doubled-radius slice estimate for a clipped origin cell, while the fixed derivative is required only on the carrier ball.

theorem CKN.Core.Step4.originClause_exists_doubled_cell_bounds_of_sws {Ω : Set Foundation.Parabolic.Vec3} {I : Set ℝ} {q R₁ : ℝ} {u : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} {Du : Foundation.Parabolic.ParabolicPoint → Fin 3 → Foundation.Parabolic.Vec3} {p : Foundation.Parabolic.ParabolicPoint → ℝ} {f : Foundation.Parabolic.ParabolicPoint → Foundation.Parabolic.Vec3} (hsol : IsSuitableWeakSolutionIntegrable Ω I q u Du p f) (hdom : closure (Foundation.Parabolic.parabolicCylinder 0 0 1) ⊆ spaceTimeSet Ω I) (hR₁ : 0 < R₁) (hR₁one : R₁ < 1) :

One measurable carrier gradient, obtained from suitability, satisfies all clipped cell estimates through twice the origin margin scale.