OAI/Geometry/RCD/Metric/RescaledBallVolume.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Uniform nearby-ball volume ratios at bounded rescaled curvature
Only the existing CD condition is used. Nonnegative curvature uses the Euclidean ratio, and negative curvature uses the exponential distortion bound. The resulting constant is chosen before the center and radius.
- theorem
OAI.RegularPointCoordinates.NoncollapsedRCD.rescaled_ball_volume_lowerline 21Source documentation
The exact polynomial lower bound behind the scale-uniform volume factor.
theorem NoncollapsedRCD.rescaled_ball_volume_lower {K : ℝ} {n : ℕ} (hX : NoncollapsedRCD K n X) (hn : 2 ≤ n) {a δ : ℝ} (ha : 0 ≤ a) (hδ : 0 < δ) (hδ1 : δ ≤ 1) (p : X) (R : ℝ) (hR : 0 < R) (hcurv : -a ≤ K*R^2) (y : X) (hy : dist y p ≤ R) : (δ/(2*Real.exp (4*Real.sqrt a)))^n*(hausdorff n X).real (ball p R) ≤ (hausdorff n X).real (ball y (δ*R)) := by …Mentions: OAI.RegularPointCoordinates.NoncollapsedRCD, OAI.RegularPointCoordinates.hausdorff
- theorem
OAI.RegularPointCoordinates.NoncollapsedRCD.rescaled_ball_volume_factorline 92