OAI/GroupTheory/PolycyclicRecognition/Analysis/ErgodicMixtureLimits.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Bounded limits through the published ergodic decomposition

Setwise barycenters are enough for the stationary-increment application. No measurable selection of a label on the components is needed.

  1. theorem OAI.PolycyclicRecognition.lintegral_eq_of_setwise_barycenter line 21

    Source documentation

    Extend a setwise decomposition to every nonnegative measurable integrand.

    theorem lintegral_eq_of_setwise_barycenter (μ : Measure X) (κ : X → Measure X)
        (hκ : ∀ s : Set X, MeasurableSet s → Measurable (fun x => κ x s))
        (hbary : ∀ s : Set X, MeasurableSet s → μ s = ∫⁻ x, κ x s ∂μ)
        (f : X → ℝ≥0∞) (hf : Measurable f) :
        ∫⁻ x, f x ∂μ = ∫⁻ x, ∫⁻ y, f y ∂κ x ∂μ := by
    …
  2. theorem OAI.PolycyclicRecognition.tendsto_lintegral_of_componentwise_bounded line 34

    Source documentation

    Uniformly bounded componentwise convergence passes through a probability barycenter, with the component map kept fixed throughout the limit.

    theorem tendsto_lintegral_of_componentwise_bounded
        (μ : Measure X) [IsProbabilityMeasure μ] (κ : X → Measure X)
        (hκ : ∀ s : Set X, MeasurableSet s → Measurable (fun x => κ x s))
        (hbary : ∀ s : Set X, MeasurableSet s → μ s = ∫⁻ x, κ x s ∂μ)
        {ι : Type*} {l : Filter ι} [l.IsCountablyGenerated]
        (f : ι → X → ℝ≥0∞) (hf : ∀ n, Measurable (f n))
        {B : ℝ≥0∞} (hB : B ≠ ⊤)
        (hbound : ∀ᶠ n in l, ∀ x, ∫⁻ y, f n y ∂κ x ≤ B)
        (hlim : ∀ x, Tendsto (fun n => ∫⁻ y, f n y ∂κ x) l (𝓝 0)) :
        Tendsto (fun n => ∫⁻ x, f n x ∂μ) l (𝓝 0) := by
    …