OAI/GroupTheory/PolycyclicRecognition/Analysis/CompactSetMeanApproximation.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

Deterministic approximation by a prescribed set of profiles

  1. theorem OAI.PolycyclicRecognition.exists_set_mean_approximation line 17

    Source documentation

    Pairwise concentration and concentration near a prescribed set give one deterministic point of that set whose mean approximation error vanishes.

    theorem exists_set_mean_approximation
        {S Y : Type*} [TopologicalSpace S] [CompactSpace S] [T2Space S]
        [MeasurableSpace S] [BorelSpace S] [PseudoMetricSpace Y]
        (F : S → Y) (hF : Continuous F) (T : Set Y) (hne : T.Nonempty)
        (μ : ℕ → ProbabilityMeasure S)
        (hpair : Tendsto (fun n => ∫ y, ∫ x, dist (F x) (F y)
          ∂(μ n : Measure S) ∂(μ n : Measure S)) atTop (𝓝 0))
        (hset : Tendsto (fun n => ∫ x, infDist (F x) T ∂(μ n : Measure S)) atTop (𝓝 0)) :
        ∃ c : ℕ → Y, (∀ n, c n ∈ T) ∧
          Tendsto (fun n => ∫ x, dist (F x) (c n) ∂(μ n : Measure S)) atTop (𝓝 0) := by
    …
  2. theorem OAI.PolycyclicRecognition.pair_mean_tendsto_zero_of_probability line 68

    Source documentation

    On a compact sample space, distance concentration in probability implies the pairwise first-moment hypothesis used above.

    theorem pair_mean_tendsto_zero_of_probability
        {S Y : Type*} [TopologicalSpace S] [CompactSpace S] [SecondCountableTopology S]
        [MeasurableSpace S] [BorelSpace S] [PseudoMetricSpace Y]
        (F : S → Y) (hF : Continuous F) (μ : ℕ → ProbabilityMeasure S)
        (hp : ∀ ε : ℝ, 0 < ε → Tendsto (fun n =>
          (μ n : Measure S).prod (μ n : Measure S) {p | ε ≤ dist (F p.1) (F p.2)})
            atTop (𝓝 0)) :
        Tendsto (fun n => ∫ y, ∫ x, dist (F x) (F y)
          ∂(μ n : Measure S) ∂(μ n : Measure S)) atTop (𝓝 0) := by
    …
  3. theorem OAI.PolycyclicRecognition.set_distance_mean_tendsto_zero_of_probability line 90

    Source documentation

    Compactness also bounds the distance to any fixed nonempty target set.

    theorem set_distance_mean_tendsto_zero_of_probability
        {S Y : Type*} [TopologicalSpace S] [CompactSpace S]
        [MeasurableSpace S] [BorelSpace S] [PseudoMetricSpace Y]
        (F : S → Y) (hF : Continuous F) (T : Set Y)
        (μ : ℕ → ProbabilityMeasure S)
        (hp : ∀ ε : ℝ, 0 < ε → Tendsto (fun n =>
          (μ n : Measure S) {x | ε ≤ infDist (F x) T}) atTop (𝓝 0)) :
        Tendsto (fun n => ∫ x, infDist (F x) T ∂(μ n : Measure S)) atTop (𝓝 0) := by
    …