OAI/Geometry/RCD/Sobolev/RadialCutoffMass.lean

GitHub source file

3 declarations, 0 contain sorry, 0 declared as axioms

Source mass from the squared-distance weak identity

Gigli (2015), Corollary 5.15, equation (5.29), supplies the local positive Laplacian defect of squared distance. Applying that defect to the explicit radial test gives this volume-drop bound directly. The only calculus premise is the actual radial pairing, obtained from the distance eikonal identity; no mass bound or radial distribution identity is assumed.

  1. theorem OAI.RegularPointCoordinates.radialPowerRep_bounds line 24
  2. theorem OAI.RegularPointCoordinates.radialPowerRep_tsupport line 46

    Source documentation

    The radial test has support strictly inside any larger working ball.

    theorem radialPowerRep_tsupport {n r R T : ℝ} (hrR : r ≤ R) (hRT : R < T) (c : X) :
        tsupport (radialPowerRep n r R c) ⊆ ball c T := by
    …

    Mentions: OAI.RegularPointCoordinates.radialPowerRep

  3. theorem OAI.RegularPointCoordinates.radial_source_cutoff_mass_le line 59

    Source documentation

    The positive squared-distance Laplacian defect has an annular volume budget, with an explicit coefficient and curvature term.

    theorem radial_source_cutoff_mass_le {n r R T curvature : ℝ}
        (hn : 0 < n) (hr : 0 < r) (hrR : r < R) (hRT : R < T)
        (hcurvature : 0 ≤ curvature) (c : X) (q : SobolevSpace μ hQ)
        (σ : Measure X) [IsFiniteMeasure σ]
        (hdefect : ∀ (ψ : SobolevSpace μ hQ) (v : X → ℝ) (C : ℝ≥0),
          LipschitzWith C v → HasCompactSupport v → tsupport v ⊆ ball c T →
          SobolevSpace.toLp μ hQ ψ =ᵐ[μ] v →
          energyForm μ hQ q ψ + (n + curvature) * (∫ x, v x ∂μ) = ∫ x, v x ∂σ)
        (hpair : ∀ᵐ x ∂μ, x ∈ ball c R →
          localGamma μ hQ q (inwardSobolev μ hQ c R) x = -dist c x)
        (hsphere : μ (sphere c r) = 0) :
        ((r ^ (-n) - R ^ (-n)) / n) * σ.real (ball c r) ≤
    …

    Mentions: OAI.RegularPointCoordinates.SobolevSpace, OAI.RegularPointCoordinates.SobolevSpace.toLp, OAI.RegularPointCoordinates.energyForm, OAI.RegularPointCoordinates.localGamma, OAI.RegularPointCoordinates.inwardSobolev