Smooth spatial slices of the regularized velocity #
The all-order Bessel lifts give integrable Fourier moments of every finite degree. Fourier inversion therefore makes every regularized velocity slice smooth in space.
theorem
ESS.lps_regR12FreqCurve_moment_integrable
(ρ : CKN.Leray.RegMollifierProfile)
(ε : ℝ)
(hε : 0 < ε)
(a : CKN.Foundation.Parabolic.Vec3 → CKN.Foundation.Parabolic.Vec3)
(ha : CKN.IsInJ a)
(t : ℝ)
(ht : 0 ≤ t)
(r : ℕ)
:
MeasureTheory.Integrable
(fun (ξ : CKN.Foundation.Parabolic.L2Vec3) => ‖ξ‖ ^ r * ‖↑↑(CKN.Leray.regR12FreqCurve ρ ε hε a ha t) ξ‖)
MeasureTheory.volume
Every polynomial moment of the Fourier transform of a
nonnegative-time regularized velocity slice is integrable
(prop:lps-smoothing).
theorem
ESS.lps_regR12Velocity_slice_contDiff
(ρ : CKN.Leray.RegMollifierProfile)
(ε : ℝ)
(hε : 0 < ε)
(a : CKN.Foundation.Parabolic.Vec3 → CKN.Foundation.Parabolic.Vec3)
(ha : CKN.IsInJ a)
(t : ℝ)
(ht : 0 ≤ t)
(i : Fin 3)
:
ContDiff ℝ ↑⊤ fun (x : CKN.Foundation.Parabolic.Vec3) => CKN.Leray.regR12Velocity ρ ε hε a ha (x, t) i
Every nonnegative-time spatial slice of the actual regularized
velocity is smooth to all orders (prop:lps-smoothing).