OAI/NumberTheory/EgyptianFractions/RationalDiscrepancy.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

  1. theorem OAI.Problem337.rational_small_interval_of_fourier line 15

    Source documentation

    Sharp lower-interval discrepancy for rational phases, using a sufficiently large common cyclic modulus. There is no common-denominator hypothesis and there are no modulus-size side conditions on the conclusion.

    theorem rational_small_interval_of_fourier {Ω : Type*} [Fintype Ω]
        (x : Ω → ℚ) (hx0 : ∀ ω, 0 ≤ x ω) (hx1 : ∀ ω, x ω < 1) (δ : ℝ)
        (hδ : 0 < δ) (hsmall : δ ≤ 1 / 65536)
        (hfourier : ∀ l : ℕ, 1 ≤ l → l ≤ ⌊1 / δ ^ 4⌋₊ →
          ‖∑ ω : Ω, (Circle.exp (2 * Real.pi * (x ω : ℝ)) : ℂ) ^ l‖ ≤
            (Fintype.card Ω : ℝ) * δ ^ 3) :
        (δ / 2) * (Fintype.card Ω : ℝ) ≤
          ((Finset.univ.filter (fun ω => (x ω : ℝ) < δ)).card : ℝ) := by
    …
  2. theorem OAI.Problem337.rational_small_interval_of_fourier_finset line 44

    Source documentation

    Finset-indexed rational discrepancy, including an empty sample set.

    theorem rational_small_interval_of_fourier_finset {Ω : Type*}
        (samples : Finset Ω) (x : Ω → ℚ)
        (hx0 : ∀ ω ∈ samples, 0 ≤ x ω) (hx1 : ∀ ω ∈ samples, x ω < 1) (δ : ℝ)
        (hδ : 0 < δ) (hsmall : δ ≤ 1 / 65536)
        (hfourier : ∀ l : ℕ, 1 ≤ l → l ≤ ⌊1 / δ ^ 4⌋₊ →
          ‖∑ ω ∈ samples, (Circle.exp (2 * Real.pi * (x ω : ℝ)) : ℂ) ^ l‖ ≤
            (samples.card : ℝ) * δ ^ 3) :
        (δ / 2) * (samples.card : ℝ) ≤
          ((samples.filter (fun ω => (x ω : ℝ) < δ)).card : ℝ) := by
    …
  3. theorem OAI.Problem337.eventually_rational_exponential_interval line 71

    Source documentation

    The sharp exponential localization form, uniform over all finite rational sample families once the scale is sufficiently large.

    theorem eventually_rational_exponential_interval {Ω : Type*}
        (η : ℝ) (hη : 0 < η) :
        ∀ᶠ w : ℝ in Filter.atTop, ∀ (samples : Finset Ω) (x : Ω → ℚ),
          (∀ ω ∈ samples, 0 ≤ x ω) → (∀ ω ∈ samples, x ω < 1) →
          (∀ l : ℕ, 1 ≤ l → l ≤ ⌊Real.exp (4 * η * w)⌋₊ →
            ‖∑ ω ∈ samples, (Circle.exp (2 * Real.pi * (x ω : ℝ)) : ℂ) ^ l‖ ≤
              (samples.card : ℝ) * Real.exp (-3 * η * w)) →
          (Real.exp (-η * w) / 2) * (samples.card : ℝ) ≤
            ((samples.filter (fun ω => (x ω : ℝ) < Real.exp (-η * w))).card : ℝ) := by
    …