OAI/Probability/InvariantIsing/Haar/PublishedInputs.lean

GitHub source file

4 declarations, 0 contain sorry, 0 declared as axioms

Haar concentration and Gaussian Poincaré inequalities.

Gromov–Milman, A topological application of the isoperimetric inequality, American Journal of Mathematics 105 (1983), 843–854, Section 1.2, Remark 2, and the special-orthogonal example in Section 3.4 give the following concentration specialization.

  1. abbrev OAI.InvariantIsing.SpecialOrthogonal line 21
  2. def OAI.InvariantIsing.frobeniusDistance line 24

    Source documentation

    Frobenius distance, with the unnormalized matrix-coordinate convention.

    def frobeniusDistance {N : ℕ} (U V : SpecialOrthogonal N) : ℝ :=
    …

    Mentions: OAI.InvariantIsing.SpecialOrthogonal

  3. def OAI.InvariantIsing.HaarConcentrationInput line 31

    Source documentation

    Haar concentration for arbitrary Frobenius-Lipschitz observables on SO(N). The constants are uniform in dimension, observable, and Lipschitz constant.

    def HaarConcentrationInput : Prop :=
    …
  4. def OAI.InvariantIsing.GaussianLipschitzVarianceInput line 55

    Source documentation

    The finite-dimensional Gaussian Poincaré inequality specialized to a globally Lipschitz function. The Euclidean norm is essential: a coordinatewise bound for the supremum norm would introduce a dimension factor.

    Published source: Bakry–Émery, Diffusions hypercontractives, Séminaire de Probabilités XIX (1985), Proposition 5, equation (20), p.198, with U(x)=x², and Corollary 2, equation (23), p.199, with the Ornstein–Uhlenbeck example on pp.199–200 (the carré-du-champ calculation is on p.186). The usual Lipschitz specialization follows by smooth approximation.

    def GaussianLipschitzVarianceInput : Prop :=
    …