Axisymmetry on the unit cylinder from analytic forcing and an axisymmetric core #
The first half of the proof of thm:main: by interior analyticity thm:analytic:interior,
spatial analyticity of the force eq:interior:force:analytic makes every slice u(·, t) real
analytic on B(1), and the identity theorem carries the exact axisymmetry on the core
eq:interior:core to all of Q, which is eq:interior:global:symmetry.
theorem
CIV.isAxisymmetricOn_unitCylinder_of_forceSpatiallyAnalytic
{q : ℝ}
{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}
{f : CKN.Foundation.Parabolic.ParabolicPoint → CKN.Foundation.Parabolic.Vec3}
(hsol : CKN.IsSuitableWeakSolution (CKN.Foundation.Parabolic.vec3Ball 0 1) (Set.Ioo (-1) 0) q u Du p f)
(hu : ContDiffOn ℝ (↑⊤) (fun (z : CKN.Foundation.Parabolic.Vec3 × ℝ) => u z) unitCylinder)
(hp : ContDiffOn ℝ (↑⊤) (fun (z : CKN.Foundation.Parabolic.Vec3 × ℝ) => p z) unitCylinder)
(hf : ContDiffOn ℝ (↑⊤) (fun (z : CKN.Foundation.Parabolic.Vec3 × ℝ) => f z) unitCylinder)
(hfa : ForceSpatiallyAnalytic f)
(hcore :
∀ t ∈ Set.Ioo (-1) 0,
∃ ρ ∈ Set.Ioo 0 1, IsAxisymmetricOn u (CKN.spaceTimeSet (CKN.Foundation.Parabolic.vec3Ball 0 ρ) {t}))
:
eq:interior:global:symmetry: a suitable weak solution on Q, smooth there, with a
spatially analytic force and an axisymmetric core at every time, is axisymmetric on Q.