OAI/Geometry/RCD/Coordinates/RegularOpenCoordinates.lean

GitHub source file

5 declarations, 0 contain sorry, 0 declared as axioms

Constructive openness of the actual harmonic coordinates

  1. theorem OAI.RegularPointCoordinates.pointed_approximation_restrict_four line 16

    Source documentation

    A centered four-ball approximation restricts to the unit ball when the error is at most half the new tolerance.

    theorem pointed_approximation_restrict_four {X E : Type*}
        [MetricSpace X] [NormedAddCommGroup E] [NormedSpace ℝ E]
        {x : X} {r epsilon : ℝ} {g : X → E} (hr : 0 < r)
        (hepsilon : epsilon ≤ 1 / 2048) (hzero : g x = 0)
        (hg : IsPointedApproximation x 0 r 4 epsilon g) :
        IsPointedApproximation x 0 r 1 (1 / 1024) g := by
    …

    Mentions: OAI.RegularPointCoordinates.IsPointedApproximation

  2. theorem OAI.RegularPointCoordinates.regular_quarter_radius line 36
  3. def OAI.RegularPointCoordinates.RegularBilinearData.quarterFrame line 54

    Source documentation

    Quarter-scale pointwise coordinate changes, extended outside the working neighborhood only to give the total function required by the open-map API.

    def quarterFrame (i : ℕ) (q : X) : Euclidean n ≃L[ℝ] Euclidean n := by
    …

    Mentions: OAI.RegularPointCoordinates.Euclidean

  4. theorem OAI.RegularPointCoordinates.RegularBilinearData.quarterFrame_eq line 59
  5. def OAI.RegularPointCoordinates.regular_open_coordinate_data line 67

    Source documentation

    The actual regular-neighborhood harmonic coordinates satisfy every hypothesis of the constructive open-map argument.

    def regular_open_coordinate_data {K : ℝ} {n : ℕ}
        (hX : NoncollapsedRCD K n X) [(hausdorff n X).Regular]
        {base : X} {a κ B J C A Cχ enlargement zeta eta : ℝ}
        {ker : ℝ → X → X → ℝ}
        {hk : IsContinuousHeatKernel (hausdorff n X) hX.quadratic ker}
        (e : RegularProjectionEnvironment hX base hk a κ B J C A Cχ enlargement zeta eta)
        (hzeta : 0 ≤ zeta) (hzetaSmall : zeta ≤ 1 / 2048)
        (hgramSmall : (n : ℝ) ^ 2 * (((5 / 3 : ℝ) * ((1 / 4 : ℝ) ^ n)⁻¹) * zeta) ≤ 3 / 4) :
        OpenCoordinateData (ball base (e.heat.radius / 1024)) e.heat.values
          (e.heat.radius / 128) (2 * (n : ℝ)) := by
    …

    Mentions: OAI.RegularPointCoordinates.NoncollapsedRCD, OAI.RegularPointCoordinates.hausdorff, OAI.RegularPointCoordinates.IsContinuousHeatKernel, OAI.RegularPointCoordinates.RegularProjectionEnvironment, OAI.RegularPointCoordinates.OpenCoordinateData