OAI/Geometry/RCD/Metric/LowerCurvatureVolume.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Scale-uniform volume comparison from nonnegative curvature

The existing CD support-volume argument gives Euclidean ball-ratio comparison when K is nonnegative. This removes dependence on |K| at large radii from the local estimates used to discharge the harmonic gradient input.

  1. theorem OAI.RegularPointCoordinates.time_le_sigma_of_nonneg_curvature line 18
  2. theorem OAI.RegularPointCoordinates.time_le_tau_of_nonneg_curvature line 41
  3. theorem OAI.RegularPointCoordinates.tau_zero_curvature line 62
  4. theorem OAI.RegularPointCoordinates.FullCD.zero_of_nonneg_curvature line 77

    Source documentation

    The nonnegative-curvature CD condition also supplies its zero-curvature specialization. This keeps the compression constants uniform when the original positive curvature is arbitrarily large.

    theorem FullCD.zero_of_nonneg_curvature {μ : Measure X} {K : ℝ} {n : ℕ}
        (hcd : FullCD μ K n) (hn : 2 ≤ n) (hK : 0 ≤ K) : FullCD μ 0 n := by
    …

    Mentions: OAI.RegularPointCoordinates.FullCD

  5. theorem OAI.RegularPointCoordinates.NoncollapsedRCD.zero_of_nonneg_curvature line 95

    Source documentation

    Preserve the metric measure structure while lowering a nonnegative curvature bound to zero.

    theorem NoncollapsedRCD.zero_of_nonneg_curvature {K : ℝ} {n : ℕ}
        (hX : NoncollapsedRCD K n X) (hn : 2 ≤ n) (hK : 0 ≤ K) :
        NoncollapsedRCD 0 n X where
    …

    Mentions: OAI.RegularPointCoordinates.NoncollapsedRCD

  6. theorem OAI.RegularPointCoordinates.FullCD.nonneg_ball_ratio_at_time line 106
  7. theorem OAI.RegularPointCoordinates.FullCD.nonneg_ball_ratio line 162