OAI/GroupTheory/PolycyclicRecognition/Analysis/TranslatedBoxMass.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

Volume ratios for translated exponential boxes

  1. theorem OAI.PolycyclicRecognition.measure_image_mul_right line 16

    Source documentation

    Right translation preserves the measure of every set, including sets whose measurability has not yet been established separately.

    theorem measure_image_mul_right {G : Type*} [Group G] [MeasurableSpace G]
        [MeasurableMul G] (μ : Measure G) [μ.IsMulRightInvariant] (S : Set G) (k : G) :
        μ ((fun x => x * k) '' S) = μ S := by
    …
  2. theorem OAI.PolycyclicRecognition.exponential_box_radius_measure line 30

    Source documentation

    Enlarging the radius of a fixed exponential box multiplies its Haar volume by exactly the corresponding power, independently of the scale.

    theorem exponential_box_radius_measure
        (e : L ≃ₗ⁅ℝ⁆ GroupLieAlgebra (𝓘(ℝ, E)) G)
        (Exp : GroupLieAlgebra (𝓘(ℝ, E)) G → G)
        (chart : GroupLieAlgebra (𝓘(ℝ, E)) G ≃ₜ G) (hchart : ∀ x, chart x = Exp x)
        {n : ℕ} (b₀ b : Basis (Fin n) ℝ L) {R : ℝ} (hR : 0 ≤ R) :
        (Measure.map ((Exp ∘ e) ∘ b₀.equivFun.symm) volume)
          (exponentialCoordinateBox (Exp ∘ e) b R) =
          ENNReal.ofReal (R ^ n) *
            (Measure.map ((Exp ∘ e) ∘ b₀.equivFun.symm) volume)
              (exponentialCoordinateBox (Exp ∘ e) b 1) := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialCoordinateBox

  3. theorem OAI.PolycyclicRecognition.translated_box_increment_mem line 52

    Source documentation

    The conjugated increment lies in a small box; hence the translated source box times that increment lies in the translated product box.

    theorem translated_box_increment_mem {G : Type*} [Group G]
        {B R : Set G} (hprod : ∀ x ∈ B, ∀ y ∈ B, x * y ∈ R)
        (k s : G) (hs : k * s * k⁻¹ ∈ B) {x : G}
        (hx : x ∈ (fun y => y * k) '' B) :
        x * s ∈ (fun y => y * k) '' R := by
    …