The actual similarity scale at the singular point #
The coordinate solves q - z^2 q^a = tau. Its positive branch tends to zero
when tau and z tend to zero together. The value assigned outside the
positive-time domain is never used in this assertion.
theorem
NavierStokes.SimilarityApproach.upperScale_continuous
{a : ℝ}
(ha1 : a < 1)
:
Continuous (upperScale a)
@[simp]
theorem
NavierStokes.SimilarityApproach.coordinateQ_tendsto_zero
{α : Type u_1}
{l : Filter α}
{tau z : α → ℝ}
{a : ℝ}
(ha : 0 < a)
(ha1 : a < 1)
(htau : Filter.Tendsto tau l (nhds 0))
(hz : Filter.Tendsto z l (nhds 0))
(hpos : ∀ᶠ (i : α) in l, 0 < tau i)
:
Filter.Tendsto (fun (i : α) => SimilarityCoordinates.coordinateQ a (tau i, z i)) l (nhds 0)
Joint approach; neither a fixed axial coordinate nor a prescribed path is required. Positive time is required eventually.
theorem
NavierStokes.SimilarityApproach.physical_q_tendsto_zero
{α : Type u_1}
{l : Filter α}
{p : α → SimilarityProfile.PhysicalPoint}
{h : ℝ}
(hh : 0 < h)
(hh1 : h < 1 / 2)
(ht : Filter.Tendsto (fun (i : α) => (p i).1) l (nhds 1))
(hz : Filter.Tendsto (fun (i : α) => (p i).2.2) l (nhds 0))
(hbefore : ∀ᶠ (i : α) in l, (p i).1 < 1)
:
Filter.Tendsto (fun (i : α) => SimilarityProfile.q h (p i)) l (nhds 0)
theorem
NavierStokes.SimilarityApproach.jet_tendsto_zero
{D : Type u_1}
{V : Type u_2}
[NormedAddCommGroup D]
[NormedSpace ℝ D]
[NormedAddCommGroup V]
[NormedSpace ℝ V]
{l : Filter D}
{q : D → ℝ}
{f : D → V}
{m : ℕ}
(hjet : DiagonalResidual.JetRate l q f m 1)
(hq : Filter.Tendsto q l (nhds 0))
:
Filter.Tendsto (iteratedFDeriv ℝ m f) l (nhds 0)
A proved positive-order estimate of an actual derivative gives its zero limit once the actual scale has the joint limit above.