OAI/Combinatorics/SharpThreshold/FourierRestrictionMass.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

  1. theorem OAI.Problem313.BiasedFourier.restricted_mass_average line 17

    Source documentation

    Exact averaging of any selected family of conditional Fourier levels.

    theorem restricted_mass_average {p : ℝ} (hp : 0 < p) (hp1 : p < 1)
        (f : (ι ⊕ κ → Bool) → ℝ) (L : Finset (Finset ι)) :
        (∑ y : κ → Bool, weight p y *
          ∑ A ∈ L, (coeff p (fun x => f (Sum.elim x y)) A) ^ 2) =
          ∑ A ∈ L, ∑ D : Finset κ, (coeff p f (A.disjSum D)) ^ 2 := by
    …

    Mentions: OAI.Problem313.BiasedFourier.weight, OAI.Problem313.BiasedFourier.coeff

  2. theorem OAI.Problem313.BiasedFourier.restricted_mass_condition line 31

    Source documentation

    The restriction identity reindexed by full supports. The condition is placed only on the free-coordinate part, never on exterior Fourier degree.

    theorem restricted_mass_condition {p : ℝ} (hp : 0 < p) (hp1 : p < 1)
        (f : (ι ⊕ κ → Bool) → ℝ) (P : Finset ι → Prop) [DecidablePred P] :
        (∑ y : κ → Bool, weight p y *
          ∑ A : Finset ι, if P A then
            (coeff p (fun x => f (Sum.elim x y)) A) ^ 2 else 0) =
          ∑ S : Finset (ι ⊕ κ), if P S.toLeft then (coeff p f S) ^ 2 else 0 := by
    …

    Mentions: OAI.Problem313.BiasedFourier.weight, OAI.Problem313.BiasedFourier.coeff

  3. theorem OAI.Problem313.BiasedFourier.restricted_low_degree_mass_average line 46

    Source documentation

    Literal real-valued conditional degree cutoff, including the case k < 1.

    theorem restricted_low_degree_mass_average {p : ℝ} (hp : 0 < p) (hp1 : p < 1)
        (f : (ι ⊕ κ → Bool) → ℝ) (k : ℝ) :
        (∑ y : κ → Bool, weight p y *
          ∑ A : Finset ι, if 1 ≤ A.card ∧ (A.card : ℝ) ≤ k then
            (coeff p (fun x => f (Sum.elim x y)) A) ^ 2 else 0) =
          ∑ S : Finset (ι ⊕ κ), if 1 ≤ S.toLeft.card ∧ (S.toLeft.card : ℝ) ≤ k then
            (coeff p f S) ^ 2 else 0 := by
    …

    Mentions: OAI.Problem313.BiasedFourier.weight, OAI.Problem313.BiasedFourier.coeff