OAI/Geometry/SurfaceImmersion/Primitive/PrimitiveFiberInverse.lean

GitHub source file

16 declarations, 0 contain sorry, 0 declared as axioms

The finite rank-one correction acts on symmetric tensors. Adding the identity on the antisymmetric summand gives an honest invertible operator on the full four-dimensional tensor fiber, without an orientation choice.

  1. def OAI.ClosedSurfaceR4.FiniteOrderSmoothing.tensorSymmetrizer line 24

    Source documentation

    Intrinsic symmetrization of a bilinear form.

    def tensorSymmetrizer : TensorFiber →L[ℝ] TensorFiber :=
    …

    Mentions: OAI.ClosedSurfaceR4.FiniteOrderSmoothing.TensorFiber

  2. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.tensorSymmetrizer_apply line 28
  3. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.tensorSymmetrizer_symmetric line 33
  4. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.tensorSymmetrizer_eq_self line 37
  5. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.tensorSymmetrizer_idempotent line 43
  6. def OAI.ClosedSurfaceR4.FiniteOrderSmoothing.finitePrimitiveOperator line 50

    Source documentation

    The actual finite supported primitive operator, in one fiber.

    def finitePrimitiveOperator (q : ι → TensorFiber →L[ℝ] ℝ)
        (psi : ι → ℝ) (xi : ι → Plane →L[ℝ] ℝ) : TensorFiber →L[ℝ] TensorFiber :=
    …

    Mentions: OAI.ClosedSurfaceR4.FiniteOrderSmoothing.TensorFiber, OAI.ClosedSurfaceR4.Plane

  7. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.finitePrimitiveOperator_apply line 54
  8. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.finitePrimitiveOperator_symmetric line 61
  9. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.finitePrimitiveOperator_symmetrizer line 70
  10. def OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator line 75
  11. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator_apply line 79
  12. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator_eq_id line 84
  13. theorem OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator_inverse_symmetric line 98

    Source documentation

    The inverse of the completed operator solves precisely the original symmetric rank-one equation; the auxiliary antisymmetric identity vanishes.

    theorem completedPrimitiveOperator_inverse_symmetric
        (q : ι → TensorFiber →L[ℝ] ℝ) (psi : ι → ℝ) (xi : ι → Plane →L[ℝ] ℝ)
        (hinv : (completedPrimitiveOperator q psi xi).IsInvertible)
        {H : TensorFiber} (hH : ∀ v w, H v w = H w v) :
        let B := (completedPrimitiveOperator q psi xi).inverse H
    …

    Mentions: OAI.ClosedSurfaceR4.FiniteOrderSmoothing.TensorFiber, OAI.ClosedSurfaceR4.Plane, OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator

  14. abbrev OAI.ClosedSurfaceR4.FiniteOrderSmoothing.PrimitiveFiberParameters line 121
  15. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator_smooth line 123
  16. theorem OAI.ClosedSurfaceR4.FiniteOrderSmoothing.compact_positive_primitive_inverse line 140

    Source documentation

    Invertibility and positivity are obtained on an actual open neighborhood of the reference cutoff/covector data, uniformly for a compact target set.

    theorem compact_positive_primitive_inverse
        (q : ι → TensorFiber →L[ℝ] ℝ) (psi₀ : ι → ℝ) (xi₀ : ι → Plane →L[ℝ] ℝ)
        (hbase : ∀ B : TensorFiber, (∀ v w, B v w = B w v) →
          finitePrimitiveOperator q psi₀ xi₀ B = B)
        {K : Set TensorFiber} (hK : IsCompact K)
        (hpos : ∀ H ∈ K, ∀ i, 0 < q i H) :
        ∃ eps : ℝ, 0 < eps ∧ ∀ z : PrimitiveFiberParameters ι,
          ‖z-(psi₀,xi₀)‖ < eps →
          (completedPrimitiveOperator q z.1 z.2).IsInvertible ∧
            ∀ H ∈ K, ∀ i, 0 < q i ((completedPrimitiveOperator q z.1 z.2).inverse H) := by
    …

    Mentions: OAI.ClosedSurfaceR4.FiniteOrderSmoothing.TensorFiber, OAI.ClosedSurfaceR4.Plane, OAI.ClosedSurfaceR4.FiniteOrderSmoothing.finitePrimitiveOperator, OAI.ClosedSurfaceR4.FiniteOrderSmoothing.PrimitiveFiberParameters, OAI.ClosedSurfaceR4.FiniteOrderSmoothing.completedPrimitiveOperator