OAI/Analysis/Unitarizability/FiniteSigns.lean

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9 declarations, 0 contain sorry, 0 declared as axioms

Finite independent signs. Expectations are explicit finite sums over all sign assignments with equal weight.

  1. def OAI.Dixmier.FiniteSigns.sign line 17
  2. def OAI.Dixmier.FiniteSigns.value line 19
  3. theorem OAI.Dixmier.FiniteSigns.sign_mgf line 21
  4. theorem OAI.Dixmier.FiniteSigns.sign_mgf_le line 33
  5. theorem OAI.Dixmier.FiniteSigns.value_smul line 43
  6. theorem OAI.Dixmier.FiniteSigns.upper_tail_mgf line 48

    Source documentation

    Finite Markov inequality for the equiprobable sign space.

    theorem upper_tail_mgf (a : J → ℝ) {t u : ℝ} (ht : 0 ≤ t) :
        (((univ.filter fun σ : J → Bool => u < value a σ).card : ℕ) : ℝ) * Real.exp (t*u) ≤
          (2 : ℝ) ^ Fintype.card J * Real.exp (t^2 * (∑ j, (a j)^2) / 2) := by
    …

    Mentions: OAI.Dixmier.FiniteSigns.value

  7. theorem OAI.Dixmier.FiniteSigns.upper_tail line 65

    Source documentation

    One-sided sign tail for coefficients of total squared size 1/k.

    theorem upper_tail (a : J → ℝ) {k u : ℝ} (hk : 0 < k) (hu : 0 < u)
        (ha : ∑ j, (a j)^2 = 1/k) :
        (((univ.filter fun σ : J → Bool => u < value a σ).card : ℕ) : ℝ) ≤
          (2 : ℝ) ^ Fintype.card J * Real.exp (-k*u^2/2) := by
    …

    Mentions: OAI.Dixmier.FiniteSigns.value

  8. theorem OAI.Dixmier.FiniteSigns.value_neg line 76
  9. theorem OAI.Dixmier.FiniteSigns.two_sided_tail line 80

    Source documentation

    The two-sided sign-tail bound as a fraction of the finite equiprobable sign space.

    theorem two_sided_tail (a : J → ℝ) {k u : ℝ} (hk : 0 < k) (hu : 0 < u)
        (ha : ∑ j, (a j)^2 = 1/k) :
        (((univ.filter fun σ : J → Bool => u < |value a σ|).card : ℕ) : ℝ) /
          (2 : ℝ)^Fintype.card J ≤ 2 * Real.exp (-k*u^2/2) := by
    …

    Mentions: OAI.Dixmier.FiniteSigns.value