The L⁵ bound and uniqueness #
The theorem thm:ess-l5-unique: a Leray–Hopf solution that is bounded in L³
in space uniformly in time lies in space-time L⁵, and every Leray–Hopf
solution with the same datum coincides with it. The local regularity theorem
thm:ess-local is its only regularity input; the short-time solution of
prop:pv-local-solution is constructed along the way.
theorem
ESS.Main.essL5Unique
(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
The L⁵ bound and uniqueness theorem thm:ess-l5-unique.