Smoothness of L∞L³ Leray–Hopf solutions #
The corollary cor:ess-smooth: a Leray–Hopf solution bounded in L³ uniformly in
time lies in space-time L⁵ (thm:ess-l5-unique), is unique, and is smooth up to
the final time by the Ladyzhenskaya–Prodi–Serrin theorem thm:lps at (5,5).
theorem
ESS.Main.essSmooth
(T : ℝ)
(a : CKN.Foundation.Parabolic.Vec3 → CKN.Foundation.Parabolic.Vec3)
(u : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3)
(Du : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → CKN.Foundation.Parabolic.Vec3)
:
CKN.IsLerayHopfSolution T a u Du →
essSup
(fun (t : ℝ) =>
∫⁻ (x : CKN.Foundation.Parabolic.Vec3), ENNReal.ofReal (CKN.Foundation.Parabolic.vec3EuclideanNorm (u (x, t))) ^ 3)
(MeasureTheory.volume.restrict (Set.Ioo 0 T)) < ⊤ →
MeasureTheory.MemLp u (ENNReal.ofReal 5) (MeasureTheory.volume.restrict (CKN.spaceTimeSet Set.univ (Set.Ioo 0 T))) ∧ (∀ (v : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3)
(Dv : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → CKN.Foundation.Parabolic.Vec3),
CKN.IsLerayHopfSolution T a v Dv →
v =ᵐ[MeasureTheory.volume.restrict (CKN.spaceTimeSet Set.univ (Set.Ioo 0 T))] u) ∧ ∃ (uSmooth : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3),
uSmooth =ᵐ[MeasureTheory.volume.restrict (CKN.spaceTimeSet Set.univ (Set.Ioo 0 T))] u ∧ ContDiffOn ℝ (↑⊤) (fun (z : CKN.Foundation.Parabolic.Vec3 × ℝ) => uSmooth z) (Set.univ ×ˢ Set.Ioc 0 T)
Smoothness of L∞L³ Leray–Hopf solutions, cor:ess-smooth.