OAI/Geometry/RCD/Transport/RadialTransportCutoff.lean

GitHub source file

4 declarations, 0 contain sorry, 0 declared as axioms

A radial power cutoff with the transport sign

The power cutoff has a compact Sobolev representative and exact chain rule. Taking exponent 2(n+4) gives the sign needed for radial transport whenever the fixed inner radius is at least two.

  1. def OAI.RegularPointCoordinates.transportCutoffExponent line 17
  2. theorem OAI.RegularPointCoordinates.transportCutoffExponent_pos line 19
  3. theorem OAI.RegularPointCoordinates.radial_transport_power_sign line 25

    Source documentation

    The actual negative radial derivative dominates both its own size and the zeroth-order transport coefficient throughout the outer annulus.

    theorem radial_transport_power_sign {n : ℕ} {a R t : ℝ}
        (hR : 2 ≤ R) (ht : R ≤ t) (ha : 0 ≤ a) (han : a ≤ (n : ℝ) + 1) :
        let β := transportCutoffExponent n
    …

    Mentions: OAI.RegularPointCoordinates.transportCutoffExponent

  4. theorem OAI.RegularPointCoordinates.radial_transport_cutoff_sign line 64

    Source documentation

    The radial power cutoff satisfies the coercive transport sign.

    theorem radial_transport_cutoff_sign {n : ℕ} {a R : ℝ}
        (hR : 2 ≤ R) (ha : 0 ≤ a) (han : a ≤ (n : ℝ) + 1) (z x : X)
        (hinner : R ≤ dist z x) (houter : dist z x ≤ 3 * R) :
        let β := transportCutoffExponent n
    …

    Mentions: OAI.RegularPointCoordinates.transportCutoffExponent