The L⁵ bound and uniqueness theorem

The short-time solution of prop:pv-local-solution from a solenoidal datum in L² ∩ L³, and thm:ess-l5-unique with the local regularity theorem thm:ess-local as its only input.

theorem ESS.pvLocalSolution {a : CKN.Foundation.Parabolic.Vec3 → CKN.Foundation.Parabolic.Vec3} (ha : CKN.IsInJ a) (ha3 : MeasureTheory.MemLp a (ENNReal.ofReal 3) MeasureTheory.volume) : ∃ (σ : ℝ), 0 < σ ∧ ∃ (U : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3) (DU : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → CKN.Foundation.Parabolic.Vec3) (p : CKN.Foundation.Parabolic.ParabolicPoint → ℝ), IsSerrinWeakSolution σ a U DU p ∧ MeasureTheory.MemLp U (ENNReal.ofReal 5) (MeasureTheory.volume.restrict (CKN.spaceTimeSet Set.univ (Set.Ioo 0 σ)))

prop:pv-local-solution: a solenoidal datum in L² ∩ L³ generates a finite-energy weak solution with pressure on a short slab, lying in space-time L⁵ there.

theorem ESS.essL5Unique_of_inputs (hE1 : ∀ (u : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3) (Du : CKN.Foundation.Parabolic.ParabolicPoint → Fin 3 → CKN.Foundation.Parabolic.Vec3) (p : CKN.Foundation.Parabolic.ParabolicPoint → ℝ), MeasureTheory.AEStronglyMeasurable u (MeasureTheory.volume.restrict (CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0))) → MeasureTheory.AEStronglyMeasurable Du (MeasureTheory.volume.restrict (CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0))) → MeasureTheory.AEStronglyMeasurable p (MeasureTheory.volume.restrict (CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0))) → essSup (fun (t : ℝ) => ∫⁻ (x : CKN.Foundation.Parabolic.Vec3) in CKN.Foundation.Parabolic.vec3Ball 0 1, ‖u (x, t)‖ₑ ^ 2) (MeasureTheory.volume.restrict (Set.Ioo (-1) 0)) < ⊤ → ∫⁻ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0), ‖u z‖ₑ ^ 2 + ‖Du z‖ₑ ^ 2 < ⊤ → MeasureTheory.MemLp p (ENNReal.ofReal (3 / 2)) (MeasureTheory.volume.restrict (CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0))) → essSup (fun (t : ℝ) => ∫⁻ (x : CKN.Foundation.Parabolic.Vec3) in CKN.Foundation.Parabolic.vec3Ball 0 1, ENNReal.ofReal (CKN.Foundation.Parabolic.vec3EuclideanNorm (u (x, t))) ^ 3) (MeasureTheory.volume.restrict (Set.Ioo (-1) 0)) < ⊤ → (∀ᵐ (t : ℝ) ∂MeasureTheory.volume.restrict (Set.Ioo (-1) 0), ∀ (i : Fin 3), CKN.HasWeakGradientOn (CKN.Foundation.Parabolic.vec3Ball 0 1) (fun (x : CKN.Vec 3) => u (x, t) i) fun (x : CKN.Vec 3) => Du (x, t) i) → (∀ ψ ∈ CKN.spaceTimeTestFunction (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0), ∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0), ∑ i : Fin 3, u z i * CKN.spatialPartial ψ i z = 0) → (∀ φ ∈ CKN.spaceTimeTestFunction (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0), ∫ (z : CKN.Foundation.Parabolic.ParabolicPoint) in CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0), -∑ i : Fin 3, u z i * CKN.timePartial (fun (y : CKN.Foundation.Parabolic.ParabolicPoint) => φ y i) z - ∑ i : Fin 3, ∑ j : Fin 3, u z i * u z j * CKN.spatialPartial (fun (y : CKN.Foundation.Parabolic.ParabolicPoint) => φ y i) j z + ∑ i : Fin 3, ∑ j : Fin 3, Du z i j * CKN.spatialPartial (fun (y : CKN.Foundation.Parabolic.ParabolicPoint) => φ y i) j z - p z * ∑ i : Fin 3, CKN.spatialPartial (fun (y : CKN.Foundation.Parabolic.ParabolicPoint) => φ y i) i z - ∑ i : Fin 3, 0 z i * φ z i = 0) → ∃ (γ : ℝ), 0 < γ ∧ γ ≤ 1 ∧ ∃ (w : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3), w =ᵐ[MeasureTheory.volume.restrict (CKN.Foundation.Parabolic.parabolicCylinder 0 0 (1 / 2))] u ∧ CKN.ParabolicHolderVecOn (closure (CKN.Foundation.Parabolic.parabolicCylinder 0 0 (1 / 2))) w γ) (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

thm:ess-l5-unique, with the local regularity theorem thm:ess-local as its only input: a Leray–Hopf solution in L^∞ L³ lies in space-time L⁵ and is the only Leray–Hopf solution with its datum.