Quadratic data for the Gaussian cutoff #
Bounded smooth cutoff factors preserve the finite quadratic data used in
lem:uc-gaussian.
theorem
ESS.ucGaussianCutoff_memLp_data
{ρ ε : ℝ}
(hρ : 0 < ρ)
(hε : 0 < ε)
{v : 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}
(hv : MeasureTheory.MemLp v 2 (MeasureTheory.volume.restrict (ucCylinder ρ)))
(hDw : MeasureTheory.MemLp Dw 2 (MeasureTheory.volume.restrict (ucCylinder ρ)))
(hD2w : MeasureTheory.MemLp D2w 2 (MeasureTheory.volume.restrict (ucCylinder ρ)))
(hDtw : MeasureTheory.MemLp Dtw 2 (MeasureTheory.volume.restrict (ucCylinder ρ)))
:
MeasureTheory.MemLp (ucCutoffField (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffDw (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dw) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffD2 (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dw D2w) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffDt (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dtw) 2
(MeasureTheory.volume.restrict (ucCylinder ρ))
The Gaussian cutoff preserves quadratic data for all three weak derivative fields on the normalized cylinder.
theorem
ESS.ucGaussianCutoff_l2_data
{ρ ε : ℝ}
(hρ : 0 < ρ)
(hε : 0 < ε)
{v : 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}
(hweak : CKN.HasSpaceTimeWeakDerivs (CKN.Foundation.Parabolic.vec3Ball 0 ρ) (Set.Ioo 0 2) v Dw D2w Dtw)
(hL2 :
∫⁻ (z : CKN.Foundation.Parabolic.ParabolicPoint) in ucCylinder ρ, ‖v z‖ₑ ^ 2 + ‖Dw z‖ₑ ^ 2 + ‖D2w z‖ₑ ^ 2 + ‖Dtw z‖ₑ ^ 2 < ⊤)
:
MeasureTheory.MemLp (ucCutoffField (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffDw (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dw) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffD2 (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dw D2w) 2
(MeasureTheory.volume.restrict (ucCylinder ρ)) ∧ MeasureTheory.MemLp (ucCutoffDt (ucSpatialCutoff ρ hρ) ucFinalTimeCutoff (ucInitialTimeCutoff ε) v Dtw) 2
(MeasureTheory.volume.restrict (ucCylinder ρ))
Finite quadratic data on the normalized cylinder give finite quadratic data after the Gaussian cutoff.