OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanCompactWords.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Compact increments in the Cartan word model

Compact sets of increments have bounded logarithms in the published global nilpotent exponential charts. This removes the coordinate-radius assumptions from the semidirect word estimate and leaves ordinary compact step data.

  1. theorem OAI.PolycyclicRecognition.exists_compact_exponential_coordinate_bound line 21

    Source documentation

    A compact subset has bounded coordinates in any global exponential chart, without choosing a norm on the abstract Lie-algebra model.

    theorem exists_compact_exponential_coordinate_bound
        {L : Type*} [LieRing L] [LieAlgebra ℝ L]
        {E G : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E]
        [TopologicalSpace G] [ChartedSpace E G] [Group G] [LieGroup (𝓘(ℝ, E)) ⊤ G]
        (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)
        {J : Type*} [Fintype J] (b : Basis J ℝ L) {K : Set G} (hK : IsCompact K) :
        ∃ R : ℝ, 0 ≤ R ∧ K ⊆ exponentialCoordinateBox (Exp ∘ e) b R := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialCoordinateBox

  2. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_compact_semidirect_word_bound line 66

    Source documentation

    Compact semidirect increments have the same polynomial endpoint bound. The only path restriction is containment of their actual Cartan prefix heights.

    theorem exists_compact_semidirect_word_bound
        (b₀ : Basis (Fin (finrank ℝ (cartanRootIdeal H))) ℝ (cartanRootIdeal H))
        (γ : M.Bases) {K : Set (N × D)} (hK : IsCompact K)
        (hφ : ∀ d, φ d = M.adjointGroupAutomorphism T eN ExpN hExpN
          (by rw [← show chartN = ExpN from funext hchartN]; exact chartN.bijective) dynkinN
          (cartanLog H eD ExpD
            (by rw [← show chartD = ExpD from funext hchartD]; exact chartD.bijective) d)) :
        ∃ (C : ℝ) (q : ℕ), 0 ≤ C ∧ ∀ {E : Set W}, IsCompact E → E.Nonempty →
          ∀ β : M.Bases,
          IsMaximizingColumnBasis (wordListCoordinates M.letter M.wordList b₀)
            (M.boxCost T hunimod eW E) β.val →
          ∀ r : ℝ, 0 ≤ r → ∀ (m : ℕ) (u : ℕ → N) (v : ℕ → D),
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.cartanLog, OAI.PolycyclicRecognition.IsMaximizingColumnBasis, OAI.PolycyclicRecognition.wordListCoordinates