OAI/GroupTheory/PolycyclicRecognition/Geometry/RayGroupContraction.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

Logarithmic contraction of the actual quotient-group action

The Lie-coordinate estimate is transported through the actual bijective exponential. Compact subsets have bounded logarithmic coordinates. The action is the exponential conjugate already identified with the descended Cartan action in ConeQuotientHaarAction.

  1. def OAI.PolycyclicRecognition.exponentialLog line 32

    Source documentation

    The logarithm in a specified Lie-algebra realization of a bijective group exponential.

    def exponentialLog : G → V :=
    …
  2. theorem OAI.PolycyclicRecognition.exponentialLog_exp line 35
  3. theorem OAI.PolycyclicRecognition.exp_exponentialLog line 39
  4. theorem OAI.PolycyclicRecognition.exponentialLog_conjugate line 45

    Source documentation

    Conjugation through the exponential acts on its logarithm by the specified Lie automorphism, exactly.

    theorem exponentialLog_conjugate (F : V ≃ₗ⁅ℝ⁆ V) (g : G) :
        exponentialLog e Exp hbij (exponentialConjugate e Exp hbij F g) =
          F (exponentialLog e Exp hbij g) := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialLog, OAI.PolycyclicRecognition.exponentialConjugate

  5. theorem OAI.PolycyclicRecognition.exists_bound_exponentialLog line 53

    Source documentation

    Compact sets in the group have uniformly bounded logarithms in each finite coordinate basis, using the actual exponential homeomorphism.

    theorem exists_bound_exponentialLog
        (chart : GroupLieAlgebra (𝓘(ℝ, E)) G ≃ₜ G) (hchart : ∀ v, chart v = Exp v)
        {J : Type*} [Fintype J] (b : Basis J ℝ V)
        {K : Set G} (hK : IsCompact K) :
        ∃ R : ℝ, 0 ≤ R ∧ ∀ g ∈ K, ‖b.equivFun (exponentialLog e Exp hbij g)‖ ≤ R := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialLog

  6. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_ray_group_compact_contraction line 80

    Source documentation

    Every fixed compact set of the actual ray quotient contracts at the polynomial-exponential rate in logarithmic coordinates.

    theorem exists_ray_group_compact_contraction
        (α : H →ₗ[ℝ] ℝ)
        (Q : NilpotentLieModel ((cartanRootIdeal H) ⧸ M.coneWordIdeal (positiveWeightRay α)))
        (Exp : GroupLieAlgebra (𝓘(ℝ, Q.modelSpace)) Q.carrier → Q.carrier)
        (hbij : Function.Bijective Exp)
        (chart : GroupLieAlgebra (𝓘(ℝ, Q.modelSpace)) Q.carrier ≃ₜ Q.carrier)
        (hchart : ∀ v, chart v = Exp v) :
        ∃ (b : Basis
            (Fin (finrank ℝ ((cartanRootIdeal H) ⧸ M.coneWordIdeal (positiveWeightRay α))))
            ℝ ((cartanRootIdeal H) ⧸ M.coneWordIdeal (positiveWeightRay α)))
          (p : ℕ) (c : ℝ), 0 < c ∧
          ∀ K : Set Q.carrier, IsCompact K → ∃ A : ℝ, 0 ≤ A ∧
    …

    Mentions: OAI.PolycyclicRecognition.NilpotentLieModel, OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.positiveWeightRay