OAI/NumberTheory/Ostmann/Characters/TreeSplitCoordinates.lean

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4 declarations, 0 contain sorry, 0 declared as axioms

Independent split coordinates on each actual leaf-product fiber

  1. def OAI.Ostmann.splitSamplesAppendEquiv line 13
  2. def OAI.Ostmann.treeLeafSplitEquiv line 30

    Source documentation

    Preorder split products are coordinates: root split first, followed by the left subtree and the right subtree. Each coordinate is an independent Haar unit even after the total leaf product is fixed.

    noncomputable def treeLeafSplitEquiv {G : Type} [CommGroup G] : (n : ℕ) → (P : G) →
        TreeLeafFiber G n P ≃ SplitSamples G (2 ^ n - 1)
      | 0, P => treeLeafFiberZeroEquiv P
      | n + 1, P => by
          let k := 2 ^ n - 1
    …

    Mentions: OAI.Ostmann.TreeLeafFiber, OAI.Ostmann.SplitSamples, OAI.Ostmann.treeLeafFiberZeroEquiv

  3. theorem OAI.Ostmann.treeLeafSplit_average line 49

    Source documentation

    Exact transport of the original conditional Haar average.

    theorem treeLeafSplit_average {G : Type} [CommGroup G] [Fintype G]
        (n : ℕ) (P : G) (F : SplitSamples G (2 ^ n - 1) → ℝ) :
        (Fintype.card (TreeLeafFiber G n P) : ℝ)⁻¹ *
            (∑ x : TreeLeafFiber G n P, F (treeLeafSplitEquiv n P x)) =
          (Fintype.card G : ℝ)⁻¹ ^ (2 ^ n - 1) * ∑ y, F y := by
    …

    Mentions: OAI.Ostmann.SplitSamples, OAI.Ostmann.TreeLeafFiber, OAI.Ostmann.treeLeafSplitEquiv

  4. theorem OAI.Ostmann.treeLeaf_sequentialSupport_le line 58

    Source documentation

    Adaptive support bounds therefore apply to the actual uniformly sampled leaves with their product fixed, before any validity restriction.

    theorem treeLeaf_sequentialSupport_le {G : Type} [CommGroup G] [Fintype G]
        (test : List G → G → Prop) (ρ : ℝ) (hρ : 0 ≤ ρ)
        (htest : ∀ past, (Fintype.card G : ℝ)⁻¹ *
          (∑ x : G, if test past x then (1 : ℝ) else 0) ≤ ρ)
        (past : List G) (n : ℕ) (P : G) :
        (Fintype.card (TreeLeafFiber G n P) : ℝ)⁻¹ *
            (∑ x : TreeLeafFiber G n P,
              sequentialSupport test past (2 ^ n - 1) (treeLeafSplitEquiv n P x)) ≤
          ρ ^ (2 ^ n - 1) := by
    …

    Mentions: OAI.Ostmann.TreeLeafFiber, OAI.Ostmann.sequentialSupport, OAI.Ostmann.treeLeafSplitEquiv