OAI/Geometry/SurfaceImmersion/Atlas/GenericCurvePhases.lean

GitHub source file

4 declarations, 0 contain sorry, 0 declared as axioms

Generic linear parts of the convex quadratic phases have only nondegenerate critical points on each prescribed regular boundary arc.

  1. lemma OAI.ClosedSurfaceR4.PhaseGeometry.curvePhaseVelocity_swap line 14
  2. lemma OAI.ClosedSurfaceR4.PhaseGeometry.curvePhaseAcceleration_swap line 20
  3. theorem OAI.ClosedSurfaceR4.PhaseGeometry.curve_phase_all_degenerate_parameters_null line 26
  4. theorem OAI.ClosedSurfaceR4.PhaseGeometry.exists_nondegenerate_curve_phases line 63

    Source documentation

    Countably many regular arcs can be handled in every prescribed open set of phase parameters.

    theorem exists_nondegenerate_curve_phases {α : Type*} [Countable α]
        (u v w : α → ℝ → CurvePlane) (hu : ∀ a, ContDiff ℝ ∞ (u a))
        (hv : ∀ a, ContDiff ℝ ∞ (v a))
        (hdu : ∀ a t, HasDerivAt (u a) (v a t) t)
        (hdv : ∀ a t, HasDerivAt (v a) (w a t) t) (L : α → ℝ)
        (U : Set CurvePlane) (hU : IsOpen U) (hne : U.Nonempty) :
        ∃ ell ∈ U, ∀ a t, v a t ≠ 0 → curvePhaseVelocity (u a) (v a) (L a) t ell = 0 →
          curvePhaseAcceleration (u a) (v a) (w a) (L a) t ell ≠ 0 := by
    …

    Mentions: OAI.ClosedSurfaceR4.PhaseGeometry.CurvePlane, OAI.ClosedSurfaceR4.PhaseGeometry.curvePhaseVelocity, OAI.ClosedSurfaceR4.PhaseGeometry.curvePhaseAcceleration