OAI/GroupTheory/PolycyclicRecognition/Algebra/FiniteOrbitAverage.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

Finite convex averages of translates

The same finite data act on actual functions and on their L2 classes. This allows the averages to be transported to a conditional component measure.

  1. structure OAI.PolycyclicRecognition.FiniteOrbitAverage line 19

    Source documentation

    A finite probability distribution on acting elements.

    structure FiniteOrbitAverage (G : Type*) where
    …
  2. def OAI.PolycyclicRecognition.FiniteOrbitAverage.apply line 32

    Source documentation

    The actual finite average, with the inverse convention of the Koopman action.

    def FiniteOrbitAverage.apply (A : FiniteOrbitAverage G) (f : X → ℝ) (x : X) : ℝ :=
    …

    Mentions: OAI.PolycyclicRecognition.FiniteOrbitAverage

  3. theorem OAI.PolycyclicRecognition.FiniteOrbitAverage.apply_nonneg line 35
  4. theorem OAI.PolycyclicRecognition.FiniteOrbitAverage.apply_le_one line 39
  5. theorem OAI.PolycyclicRecognition.FiniteOrbitAverage.measurable_apply line 48
  6. def OAI.PolycyclicRecognition.FiniteOrbitAverage.onL2 line 57

    Source documentation

    The same average of the actual unitary operators.

    def FiniteOrbitAverage.onL2 (A : FiniteOrbitAverage G) (v : Lp ℝ 2 μ) : Lp ℝ 2 μ :=
    …

    Mentions: OAI.PolycyclicRecognition.FiniteOrbitAverage

  7. theorem OAI.PolycyclicRecognition.exists_finiteOrbitAverage line 61

    Source documentation

    Every vector in the convex hull of an orbit has finite averaging data.

    theorem exists_finiteOrbitAverage (v w : Lp ℝ 2 μ)
        (hw : w ∈ convexHull ℝ (range (fun g : G => stationaryPullback μ g v))) :
        ∃ A : FiniteOrbitAverage G, A.onL2 μ v = w := by
    …

    Mentions: OAI.PolycyclicRecognition.stationaryPullback, OAI.PolycyclicRecognition.FiniteOrbitAverage

  8. theorem OAI.PolycyclicRecognition.FiniteOrbitAverage.onL2_coe line 79

    Source documentation

    Pointwise representatives of the finite Hilbert average.

    theorem FiniteOrbitAverage.onL2_coe (A : FiniteOrbitAverage G) (v : Lp ℝ 2 μ) :
        (A.onL2 μ v : X → ℝ) =ᵐ[μ] A.apply v := by
    …

    Mentions: OAI.PolycyclicRecognition.FiniteOrbitAverage