OAI/GroupTheory/PolycyclicRecognition/Geometry/LieHomDifferential.lean

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4 declarations, 0 contain sorry, 0 declared as axioms

Differential information at the identity of a Lie homomorphism

  1. theorem OAI.PolycyclicRecognition.mdifferentiable_hom_of_mdifferentiableAt_one line 19

    Source documentation

    Differentiability at the identity suffices for a group homomorphism.

    theorem mdifferentiable_hom_of_mdifferentiableAt_one (φ : G →* H)
        (hφ : MDifferentiableAt (𝓘(ℝ, E)) (𝓘(ℝ, F)) φ 1) :
        MDifferentiable (𝓘(ℝ, E)) (𝓘(ℝ, F)) φ := by
    …
  2. theorem OAI.PolycyclicRecognition.contMDiff_hom_of_contMDiffAt_one line 39

    Source documentation

    The same translation argument propagates smoothness from the identity.

    theorem contMDiff_hom_of_contMDiffAt_one (φ : G →* H)
        (hφ : ContMDiffAt (𝓘(ℝ, E)) (𝓘(ℝ, F)) ∞ φ 1) :
        ContMDiff (𝓘(ℝ, E)) (𝓘(ℝ, F)) ∞ φ := by
    …
  3. theorem OAI.PolycyclicRecognition.IsGroupExponential.map_of_mdifferentiableAt_one line 58
  4. theorem OAI.PolycyclicRecognition.hom_eq_of_exponential_surjective line 69

    Source documentation

    In exponential coordinates, a homomorphism is determined by its differential at the identity.

    theorem hom_eq_of_exponential_surjective [T2Space H]
        {ExpG : GroupLieAlgebra (𝓘(ℝ, E)) G → G}
        {ExpH : GroupLieAlgebra (𝓘(ℝ, F)) H → H}
        (hG : IsGroupExponential ExpG) (hH : IsGroupExponential ExpH)
        (hExpG : Function.Surjective ExpG)
        (φ ψ : G →* H)
        (hφ : MDifferentiableAt (𝓘(ℝ, E)) (𝓘(ℝ, F)) φ 1)
        (hψ : MDifferentiableAt (𝓘(ℝ, E)) (𝓘(ℝ, F)) ψ 1)
        (hderiv : ∀ v, mfderiv (𝓘(ℝ, E)) (𝓘(ℝ, F)) φ 1 v =
          mfderiv (𝓘(ℝ, E)) (𝓘(ℝ, F)) ψ 1 v) : φ = ψ := by
    …