OAI/Geometry/RCD/Coordinates/VolumeProfileRegularity.lean
5 declarations, 0 contain sorry, 0 declared as axioms
Absolute continuity of the Euclidean-normalized volume profile
Bishop--Gromov and a positive Lipschitz comparison model make ball volume Lipschitz on every compact interval of positive radii. Multiplication by the smooth Euclidean normalization then gives the absolute continuity needed by the radial source budget.
- theorem
OAI.RegularPointCoordinates.volume_profile_lipschitzOnline 22 - theorem
OAI.RegularPointCoordinates.contDiff_one_comparisonModelVolumeline 63Source documentation
The fixed negative-curvature comparison volume is continuously differentiable.
theorem contDiff_one_comparisonModelVolume (m : ℕ) (c : ℝ) : ContDiff ℝ 1 (comparisonModelVolume m c) := by … - theorem
OAI.RegularPointCoordinates.ball_volume_absolutelyContinuousline 83Source documentation
Ball volume is absolutely continuous away from radius zero under the published Bishop--Gromov comparison with the explicit model.
theorem ball_volume_absolutelyContinuous {μ : Measure X} (m : ℕ) {c : ℝ} (hc : 0 ≤ c) (hBG : BallVolumeComparison μ (comparisonModelVolume m c)) (x : X) {a b : ℝ} (ha : 0 < a) (hab : a ≤ b) (hfin : μ (ball x b) ≠ ∞) : AbsolutelyContinuousOnInterval (fun t => μ.real (ball x t)) a b := by …Mentions: OAI.RegularPointCoordinates.BallVolumeComparison, OAI.RegularPointCoordinates.comparisonModelVolume
- theorem
OAI.RegularPointCoordinates.normalized_ball_volume_absolutelyContinuousline 110Source documentation
Euclidean-normalized volume retains absolute continuity on positive radius intervals; this does not assume monotonicity of that normalization.
theorem normalized_ball_volume_absolutelyContinuous {μ : Measure X} (m : ℕ) {c : ℝ} (hc : 0 ≤ c) (hBG : BallVolumeComparison μ (comparisonModelVolume m c)) (x : X) {a b : ℝ} (ha : 0 < a) (hab : a ≤ b) (hfin : μ (ball x b) ≠ ∞) : AbsolutelyContinuousOnInterval (fun t => μ.real (ball x t) / t ^ (m + 1)) a b := by …Mentions: OAI.RegularPointCoordinates.BallVolumeComparison, OAI.RegularPointCoordinates.comparisonModelVolume
- theorem
OAI.RegularPointCoordinates.sphere_measure_zero_of_comparisonline 129Source documentation
Bishop--Gromov with a positive continuous model excludes mass on every positive-radius sphere, not merely almost every sphere.
theorem sphere_measure_zero_of_comparison {model : ℝ → ℝ} (hBG : BallVolumeComparison μ model) (hcont : Continuous model) (x : X) {r : ℝ} (hr : 0 < r) (hmodel : 0 < model r) : μ (sphere x r) = 0 := by …