OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanBoxMaps.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Propagating root-action bounds through Cartan boxes

A Lie map which preserves the letter root spaces has a polynomial bound in every maximizing box. The proof propagates the bounds on letters through actual bracket words, then through their coordinate basis. This is the algebraic step in the box-conjugation estimate.

  1. theorem OAI.PolycyclicRecognition.evalBracketWord_exp_smul line 25

    Source documentation

    Independent exponential scaling of letters multiplies a word by the exponential of the sum of its letter exponents.

    theorem evalBracketWord_exp_smul (X : I → L) (s : I → ℝ) (r : ℝ) (w : FreeMagma I) :
        evalBracketWord (fun i => Real.exp (r * s i) • X i) w =
          Real.exp (r * bracketWordExponent s w) • evalBracketWord X w := by
    …

    Mentions: OAI.PolycyclicRecognition.evalBracketWord, OAI.PolycyclicRecognition.bracketWordExponent

  2. theorem OAI.PolycyclicRecognition.norm_basis_linearMap_le line 38

    Source documentation

    A bound on the images of basis vectors bounds the full linear map in the coordinate maximum norm.

    theorem norm_basis_linearMap_le {J : Type*} [Fintype J] (b : Basis J ℝ L)
        (F : L →ₗ[ℝ] L) {K : ℝ}
        (hF : ∀ j, ‖b.equivFun (F (b j))‖ ≤ K) (v : L) :
        ‖b.equivFun (F v)‖ ≤ (Fintype.card J : ℝ) * K * ‖b.equivFun v‖ := by
    …
  3. theorem OAI.PolycyclicRecognition.image_exponentialCoordinateBox_subset line 57

    Source documentation

    A coordinate bound transfers to the exponential image when the maps intertwine the exponential.

    theorem image_exponentialCoordinateBox_subset
        {G J : Type*} [Fintype J] (b : Basis J ℝ L) (Exp : L → G)
        (F : L →ₗ[ℝ] L) (f : G → G) (hcomm : ∀ x, f (Exp x) = Exp (F x))
        {A : ℝ} (hA : 0 ≤ A) (hF : ∀ x, ‖b.equivFun (F x)‖ ≤ A * ‖b.equivFun x‖)
        (R : ℝ) : f '' exponentialCoordinateBox Exp b R ⊆ exponentialCoordinateBox Exp b (A * R) := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialCoordinateBox

  4. def OAI.PolycyclicRecognition.CartanWordModel.wordDegreeBound line 75

    Source documentation

    A fixed degree bound for the finite list of actual words.

    def wordDegreeBound : ℕ := ∑ w : M.wordList, bracketWordLength (w : FreeMagma (Fin M.letterCount))
    …

    Mentions: OAI.PolycyclicRecognition.bracketWordLength

  5. theorem OAI.PolycyclicRecognition.CartanWordModel.word_degrees_le line 78
  6. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_box_lieMap_bound line 88

    Source documentation

    Root-space preservation and a bound on the unscaled letter images imply a uniform polynomial bound on a Lie map in every maximizing scaled box.

    theorem exists_box_lieMap_bound
        (b₀ : Basis (Fin (finrank ℝ (cartanRootIdeal H))) ℝ (cartanRootIdeal H)) :
        ∃ A : ℝ, 0 ≤ A ∧ ∀ {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 → ∀ (F : cartanRootIdeal H →ₗ⁅ℝ⁆ cartanRootIdeal H)
            (K : ℝ), 0 ≤ K →
          (∀ i, (F (M.letter i) : L) ∈ LieAlgebra.rootSpace H (M.weight i)) →
          (∀ i, ‖(WordBasisSelections.basis M.letter M.wordList β).equivFun
            (F (M.letter i))‖ ≤ K) →
          ∀ v, ‖(M.boxBasis T hunimod eW E β r).equivFun (F v)‖ ≤
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.IsMaximizingColumnBasis, OAI.PolycyclicRecognition.wordListCoordinates, OAI.PolycyclicRecognition.WordBasisSelections.basis

  7. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_groupBox_automorphism_bound line 159

    Source documentation

    The Lie-map estimate gives a bound on the actual nilpotent group boxes, using the already constructed group automorphism.

    theorem exists_groupBox_automorphism_bound
        (b₀ : Basis (Fin (finrank ℝ (cartanRootIdeal H))) ℝ (cartanRootIdeal H)) :
        ∃ A : ℝ, 0 ≤ A ∧ ∀ {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 → ∀ (F : cartanRootIdeal H ≃ₗ⁅ℝ⁆ cartanRootIdeal H)
            (K : ℝ), 0 ≤ K →
          (∀ i, (F (M.letter i) : L) ∈ LieAlgebra.rootSpace H (M.weight i)) →
          (∀ i, ‖(WordBasisSelections.basis M.letter M.wordList β).equivFun
            (F (M.letter i))‖ ≤ K) →
          ∀ R : ℝ,
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.IsMaximizingColumnBasis, OAI.PolycyclicRecognition.wordListCoordinates, OAI.PolycyclicRecognition.WordBasisSelections.basis