Differential inequality under parabolic scaling #
The almost-everywhere heat inequality in lem:uc-gaussian transfers through
the normalized parabolic coordinates.
theorem
ESS.uc_scaled_weak_heat_ae_bound
(x₀ : CKN.Foundation.Parabolic.Vec3)
(scale ρ c₁ : ℝ)
(hscale : 0 < scale)
(hscale1 : scale ≤ 1)
(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)
(hsource :
∀ᵐ (z :
CKN.Foundation.Parabolic.ParabolicPoint) ∂MeasureTheory.volume.restrict
(CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball x₀ (scale * ρ)) (Set.Ioo 0 (scale ^ 2 * 2))), CKN.Foundation.Parabolic.vec3EuclideanNorm (ucWeakHeatVector D2w Dtw z) ≤ c₁ * (CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) + √(CKN.spatialGradientSq w Dw z)))
:
∀ᵐ (z : CKN.Foundation.Parabolic.ParabolicPoint) ∂MeasureTheory.volume.restrict (ucCylinder ρ), CKN.Foundation.Parabolic.vec3EuclideanNorm
(ucWeakHeatVector (ucScaledD2w x₀ scale D2w) (ucScaledDtw x₀ scale Dtw) z) ≤ c₁ * scale * (CKN.Foundation.Parabolic.vec3EuclideanNorm (ucScaledField x₀ scale w z) + √(CKN.spatialGradientSq (ucScaledField x₀ scale w) (ucScaledDw x₀ scale Dw) z))
The differential inequality is preserved almost everywhere under the subunit parabolic dilation.