Weak derivatives after compact zero extension #
A compactly supported field with globally square-integrable derivative data inherits its weak identities on every larger cylinder containing that data.
theorem
ESS.bu_weak_extend_compact
{Ω Ω' : Set CKN.Foundation.Parabolic.Vec3}
{I I' : Set ℝ}
{K : Set CKN.Foundation.Parabolic.ParabolicPoint}
(hΩ : IsOpen Ω)
(hI : IsOpen I)
(hKcompact : IsCompact K)
(hKsource : K ⊆ CKN.spaceTimeSet Ω I)
(hKtarget : K ⊆ CKN.spaceTimeSet Ω' I')
(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)
(hzero : ∀ z ∉ K, w z = 0 ∧ Dw z = 0 ∧ D2w z = 0 ∧ Dtw z = 0)
(hweak : CKN.HasSpaceTimeWeakDerivs Ω I w Dw D2w Dtw)
(hmem :
MeasureTheory.MemLp w 2 MeasureTheory.volume ∧ MeasureTheory.MemLp Dw 2 MeasureTheory.volume ∧ MeasureTheory.MemLp D2w 2 MeasureTheory.volume ∧ MeasureTheory.MemLp Dtw 2 MeasureTheory.volume)
:
CKN.HasSpaceTimeWeakDerivs Ω' I' w Dw D2w Dtw
Compactly supported weak derivative data extend from a source cylinder to a target cylinder containing their support.