OAI/Combinatorics/PerfectMatching/Duality.lean

GitHub source file

10 declarations, 0 contain sorry, 0 declared as axioms

Finite exponential tilts, partition functions, and entropy duality on a face.

  1. def OAI.MatchingEntropy.partition line 19

    Source documentation

    Finite exponential partition function, based on a probability law p.

    def partition {ι : Type*} [Fintype ι] (p a : ι → ℝ) (t : ℝ) : ℝ :=
    …
  2. def OAI.MatchingEntropy.tiltedLaw line 22
  3. theorem OAI.MatchingEntropy.partition_pos line 25
  4. theorem OAI.MatchingEntropy.partition_zero line 32
  5. theorem OAI.MatchingEntropy.tiltedLaw_mem_simplex line 36
  6. theorem OAI.MatchingEntropy.entropy_partition_bound line 46

    Source documentation

    Gibbs' variational inequality for the explicit finite partition function, including all boundary laws supported on p.

    theorem entropy_partition_bound {ι : Type*} [Fintype ι] {p q : ι → ℝ}
        (hp : p ∈ probabilitySimplex ι) (hq : q ∈ probabilitySimplex ι)
        (hsupp : ∀ i, p i = 0 → q i = 0) (a : ι → ℝ) (t : ℝ) :
        entropy q ≤ Real.log (partition p a t) - ∑ i, q i*Real.log (p i) -
          t * ∑ i, q i*a i := by
    …

    Mentions: OAI.MatchingEntropy.probabilitySimplex, OAI.MatchingEntropy.entropy, OAI.MatchingEntropy.partition

  7. def OAI.MatchingEntropy.linearScore line 78

    Source documentation

    A score affine in the matching vector; the constant permits centering without changing the duality calculation.

    def linearScore (G : LooplessGraph V E) (u : E → ℝ) (c : ℝ) (M : G.Matching) : ℝ :=
    …
  8. theorem OAI.MatchingEntropy.sum_mean_assoc line 82
  9. theorem OAI.MatchingEntropy.linearScore_expectation line 93
  10. theorem OAI.MatchingEntropy.matching_entropy_dual_bound line 105

    Source documentation

    A genuine upper bound on the actual maximum entropy at every mean in the optimizer's face. This is proved from Gibbs' inequality, not assumed as a replacement definition of H.

    theorem matching_entropy_dual_bound (G : LooplessGraph V E) {y : E → ℝ}
        {p : G.Matching → ℝ} (hp : p ∈ G.feasibleLaws y)
        (hopt : entropy p = maxMatchingEntropy G y)
        {r : G.Matching → ℝ} (hr : r ∈ probabilitySimplex G.Matching)
        (hrsupport : ∀ M, p M = 0 → r M = 0)
        (u : E → ℝ) (c t : ℝ) :
        maxMatchingEntropy G (G.mean r) ≤
          Real.log (partition p (linearScore G u c) t) - ∑ M, r M * Real.log (p M) -
            t * ∑ M, r M * linearScore G u c M := by
    …

    Mentions: OAI.MatchingEntropy.entropy, OAI.MatchingEntropy.maxMatchingEntropy, OAI.MatchingEntropy.probabilitySimplex, OAI.MatchingEntropy.partition, OAI.MatchingEntropy.linearScore