Suitability on a fixed rescaled cylinder #
The original suitable solution restricts and rescales to every fixed bounded
past cylinder once the scale is small enough (prop:blowup-limit).
theorem
ESS.blowupFields_eq_rescale_on_cylinder
(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)
(x₀ : CKN.Foundation.Parabolic.Vec3)
(t₀ r ρ a : ℝ)
(hx₀ : CKN.Foundation.Parabolic.vec3EuclideanNorm x₀ ≤ 1 / 2)
(ht₀ : t₀ ∈ Set.Icc (-(1 / 4)) 0)
(hr : 0 < r)
(hspace : r * ρ < 1 / 4)
(htime : r ^ 2 * -a < 3 / 4)
:
Set.EqOn (blowupVelocity x₀ t₀ r u) (parabolicRescaleVelocity x₀ t₀ r u)
(CKN.Foundation.Parabolic.vec3Ball 0 ρ ×ˢ Set.Ioo a 0) ∧ Set.EqOn (blowupGradient x₀ t₀ r Du) (parabolicRescaleGradient x₀ t₀ r Du)
(CKN.Foundation.Parabolic.vec3Ball 0 ρ ×ˢ Set.Ioo a 0) ∧ Set.EqOn (blowupPressure x₀ t₀ r p) (parabolicRescalePressure x₀ t₀ r p)
(CKN.Foundation.Parabolic.vec3Ball 0 ρ ×ˢ Set.Ioo a 0)
On each sufficiently small fixed cylinder, the zero-extended fields agree pointwise with the ordinary rescalings used for suitability.
theorem
ESS.blowupRescale_suitable_on_cylinder
(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)
(hSuitable : CKN.IsSuitableWeakSolution (CKN.Foundation.Parabolic.vec3Ball 0 (3 / 4)) (Set.Ioo (-1) 0) 3 u Du p 0)
(x₀ : CKN.Foundation.Parabolic.Vec3)
(t₀ r ρ a : ℝ)
(hx₀ : CKN.Foundation.Parabolic.vec3EuclideanNorm x₀ ≤ 1 / 2)
(ht₀ : t₀ ∈ Set.Icc (-(1 / 4)) 0)
(hr : 0 < r)
(hρ : 0 < ρ)
(ha : a < 0)
(hspace : r * ρ < 1 / 4)
(htime : r ^ 2 * -a < 3 / 4)
:
CKN.IsSuitableWeakSolution (CKN.Foundation.Parabolic.vec3Ball 0 ρ) (Set.Ioo a 0) 3 (parabolicRescaleVelocity x₀ t₀ r u)
(parabolicRescaleGradient x₀ t₀ r Du) (parabolicRescalePressure x₀ t₀ r p) 0
Navier--Stokes rescaling preserves suitability on a fixed past cylinder inside the rescaled source region.
theorem
ESS.blowupRescale_eventually_suitable_on_cylinder
(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)
(hSuitable : CKN.IsSuitableWeakSolution (CKN.Foundation.Parabolic.vec3Ball 0 (3 / 4)) (Set.Ioo (-1) 0) 3 u Du p 0)
(x₀ : CKN.Foundation.Parabolic.Vec3)
(t₀ ρ a : ℝ)
(r : ℕ → ℝ)
(hx₀ : x₀ ∈ closure (CKN.Foundation.Parabolic.vec3Ball 0 (1 / 2)))
(ht₀ : t₀ ∈ Set.Icc (-(1 / 4)) 0)
(hr : ∀ (k : ℕ), 0 < r k)
(hr0 : Filter.Tendsto r Filter.atTop (nhds 0))
(hρ : 0 < ρ)
(ha : a < 0)
:
∀ᶠ (k : ℕ) in Filter.atTop, CKN.IsSuitableWeakSolution (CKN.Foundation.Parabolic.vec3Ball 0 ρ) (Set.Ioo a 0) 3
(parabolicRescaleVelocity x₀ t₀ (r k) u) (parabolicRescaleGradient x₀ t₀ (r k) Du)
(parabolicRescalePressure x₀ t₀ (r k) p) 0
The ordinary rescalings form a tail of suitable solutions on each fixed bounded past cylinder.