OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanRayFactorContraction.lean

GitHub source file

3 declarations, 0 contain sorry, 0 declared as axioms

Compact increments and contraction for the actual Cartan factors

  1. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_compact_factor_quotient_orbit line 25

    Source documentation

    Compact ambient increments have compact quotient images. This uses compact lifts of the actual factors, so no continuity of an arbitrarily chosen factorization or permutation-valued action is assumed.

    theorem exists_compact_factor_quotient_orbit
        {Q : Type*} [Group Q] [TopologicalSpace Q]
        (π : F.N.carrier →* Q) (hπ : Continuous π)
        (α : F.D.carrier →* MulAut Q) (act : G →* Equiv.Perm Q)
        (hact : ∀ u d q, act (F.inclusionN u * F.inclusionD d) q = π u * α d q)
        {K : Set G} (hK : IsCompact K) :
        ∃ C : Set Q, IsCompact C ∧ ∀ g ∈ K, act g 1 ∈ C := by
    …
  2. theorem OAI.PolycyclicRecognition.CartanWordModel.factor_quotient_action_eq_exponential line 59

    Source documentation

    The quotient action of each actual Cartan factor is the exponential of its induced Lie action, with the actual Cartan logarithm.

    theorem factor_quotient_action_eq_exponential (d : F.D.carrier) (q : Q.carrier) :
        α d q = exponentialConjugate Q.equiv ExpQ hbijQ
          (M.coneAdjointAutomorphism T (positiveWeightRay α₀) (positiveWeightRay_add α₀)
            (cartanLog H F.D.equiv F.ExpD hbijD d)) q := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialConjugate, OAI.PolycyclicRecognition.positiveWeightRay, OAI.PolycyclicRecognition.positiveWeightRay_add, OAI.PolycyclicRecognition.cartanLog

  3. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_ray_factor_compact_contraction line 93

    Source documentation

    The contraction estimate is expressed directly in a basis of the actual tangent algebra and in the actual Cartan factor coordinates.

    theorem exists_ray_factor_compact_contraction :
        ∃ (b : Basis
            (Fin (finrank ℝ ((cartanRootIdeal H) ⧸ M.coneWordIdeal (positiveWeightRay α₀))))
            ℝ (GroupLieAlgebra (𝓘(ℝ, Q.modelSpace)) Q.carrier)) (p : ℕ) (rate : ℝ),
          0 < rate ∧ ∀ K : Set Q.carrier, IsCompact K → ∃ A : ℝ, 0 ≤ A ∧
            ∀ d : F.D.carrier,
              α₀ (cartanLog H F.D.equiv F.ExpD hbijD d) ≤ 0 → ∀ q ∈ K,
              ‖b.equivFun (chartQ.symm (α d q))‖ ≤
                A * (1 + ‖(finBasis ℝ H).equivFun
                  (cartanLog H F.D.equiv F.ExpD hbijD d)‖) ^ p *
                  Real.exp (rate * α₀ (cartanLog H F.D.equiv F.ExpD hbijD d)) := by
    …

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