OAI/Geometry/SurfaceImmersion/Atlas/AtlasNormalProjectionBounds.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

The atlas projection is a convex sum of the actual pointwise normal projections. Local exterior estimates therefore pass to the global field.

  1. def OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.chartProjectedNormal line 18
  2. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.localizedNormalField_at_source line 25
  3. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.restored_localProjectedNormal line 32
  4. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.projectedNormalField_eq_sum line 52
  5. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.projectedNormalField_sub_eq line 61
  6. theorem OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.projectedNormalField_sub_bound line 69

    Source documentation

    A local exterior error is not multiplied by the number of atlas patches: the squared weights add to one.

    theorem projectedNormalField_sub_bound (F n : M → Space) (p : M) {ε : ℝ}
        (hlocal : ∀ i : A.centers, A.weight i p ≠ 0 →
          ‖A.chartProjectedNormal i F n p - n p‖ ≤ ε) :
        ‖A.projectedNormalField F n p - n p‖ ≤ ε := by
    …

    Mentions: OAI.ClosedSurfaceR4.Space

  7. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.SmoothingAtlas.projectedNormalField_ne_zero line 86
  8. theorem OAI.ClosedSurfaceR4.GeometryPreservation.compact_raw_normal_projection line 101

    Source documentation

    Uniform stability of the unnormalized projection on a compact family of old tangent frames. This is the estimate used before normalizing the finite-atlas sum.

    theorem compact_raw_normal_projection {X : Type*} [TopologicalSpace X] [CompactSpace X]
        {A B n : X → Vec} (hA : Continuous A) (hB : Continuous B) (hn : Continuous n)
        (hD : ∀ x, gramDet (A x) (B x) ≠ 0)
        (hunit : ∀ x, n x ⬝ᵥ n x = 1)
        (hAn : ∀ x, A x ⬝ᵥ n x = 0) (hBn : ∀ x, B x ⬝ᵥ n x = 0)
        {ε : ℝ} (hε : 0 < ε) :
        ∃ δ : ℝ, 0 < δ ∧ ∀ x, ∀ A' B' : Vec,
          ‖A'-A x‖ < δ → ‖B'-B x‖ < δ →
          gramDet A' B' ≠ 0 ∧ ‖realNormalPart A' B' (n x)-n x‖ < ε := by
    …