Integrability on the physical Gaussian cylinder #
Weak derivatives and quadratic growth give finite velocity energy on every bounded averaging cylinder inside the positive half-space.
theorem
ESS.bu_short_metric_average_integrable
(M : ℝ)
(X : CKN.Foundation.Parabolic.Vec3)
(t : ℝ)
(hX : 2 < X 2)
(ht : 0 < t)
(htsmall : t < 1 / 12)
(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)
(hweak : CKN.HasSpaceTimeWeakDerivs {x : CKN.Foundation.Parabolic.Vec3 | 0 < x 2} (Set.Ioo 0 1) w Dw D2w Dtw)
(hL2 :
∀ S ⊆ CKN.spaceTimeSet {x : CKN.Foundation.Parabolic.Vec3 | 0 < x 2} (Set.Ioo 0 1),
Bornology.IsBounded S →
∫⁻ (z : CKN.Foundation.Parabolic.ParabolicPoint) in S, ‖Dw z‖ₑ ^ 2 + ‖D2w z‖ₑ ^ 2 + ‖Dtw z‖ₑ ^ 2 < ⊤)
(hgrowth :
∀ z ∈ CKN.spaceTimeSet {x : CKN.Foundation.Parabolic.Vec3 | 0 < x 2} (Set.Ioo 0 1),
CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) ≤ Real.exp (M * CKN.Foundation.Parabolic.vec3EuclideanNorm z.1 ^ 2))
:
MeasureTheory.IntegrableOn
(fun (z : CKN.Foundation.Parabolic.ParabolicPoint) => CKN.Foundation.Parabolic.vec3EuclideanNorm (w z) ^ 2)
(CKN.spaceTimeSet (Metric.ball X √(3 * t)) (Set.Ioo t (5 * t / 2))) MeasureTheory.volume
The velocity square is integrable on the physical metric Gaussian
averaging cylinder (lem:bu-small-time).