Local energy estimate for a parabolic differential inequality #
This file proves the estimate in lem:caccioppoli.
theorem
ESS.caccioppoli
(x : CKN.Foundation.Parabolic.Vec3)
(t r c₁ : ℝ)
(hr : 0 < r)
(hc₁ : 0 ≤ c₁)
{w : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3}
{Dw : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → CKN.Foundation.Parabolic.Vec3}
{D2w : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → Fin 3 → CKN.Foundation.Parabolic.Vec3}
{Dtw : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3}
(hderiv :
CKN.HasSpaceTimeWeakDerivs (CKN.Foundation.Parabolic.vec3Ball x (2 * r)) (Set.Ioo t (t + 4 * r ^ 2)) w Dw D2w Dtw)
(hL2 :
∫⁻ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball x (2 * r)) (Set.Ioo t (t + 4 * r ^ 2)), ‖w z‖ₑ ^ 2 + ‖Dw z‖ₑ ^ 2 + ‖D2w z‖ₑ ^ 2 + ‖Dtw z‖ₑ ^ 2 < ⊤)
(hineq :
∀ᵐ (z :
CKN.Foundation.Parabolic.ParabolicPoint) ∂MeasureTheory.volume.restrict
(CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball x (2 * r)) (Set.Ioo t (t + 4 * r ^ 2))), (CKN.Foundation.Parabolic.vec3EuclideanNorm fun (i : Fin 3) => Dtw z i + ∑ j : Fin 3, D2w z i j j) ≤ c₁ * (CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) + √(CKN.spatialGradientSq w Dw z)))
:
∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball x r) (Set.Ioo t (t + r ^ 2)), CKN.spatialGradientSq w Dw z ≤ 256 * (1 + c₁ ^ 2 + 1 / r ^ 2) * ∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball x (2 * r)) (Set.Ioo t (t + 4 * r ^ 2)), CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) ^ 2
The local energy estimate for a vector field satisfying a backward parabolic
differential inequality (lem:caccioppoli). The integrals are real Bochner
integrals; the stated weak derivative and square-integrability hypotheses make
their integrands integrable on the indicated cylinders.