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TauCeti.Geometry.Lie.Functor

The Lie functor on smooth homomorphisms #

The differential at the identity of a smooth Lie-group homomorphism induces a Lie-algebra homomorphism between left-invariant derivations. Smooth homomorphisms carry their differentiability proof in ContMDiffMonoidMorphism; identity and composition complete that bundled morphism API. The resulting Lie map preserves identities and composition and is natural with respect to the Lie-group exponential.

References #

Main results #

theorem ContMDiffMonoidMorphism.groupLieAlgebraMap_lie {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [CompleteSpace E] [CompleteSpace E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (X Y : GroupLieAlgebra I G) :

The differential at the identity of a smooth homomorphism preserves the Lie bracket of the tangent Lie algebras.

noncomputable def lieMap {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') :

The Lie functor on morphisms: the differential at the identity of a smooth homomorphism.

Instances For
    @[simp]

    Under evaluation at the identity, lieMap is the manifold differential of the homomorphism.

    @[simp]

    The Lie map of the identity homomorphism is the identity Lie-algebra homomorphism.

    @[simp]
    theorem lieMap_comp {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] {E'' : Type u_7} [NormedAddCommGroup E''] [NormedSpace ℝ E''] {H'' : Type u_8} [TopologicalSpace H''] {I'' : ModelWithCorners ℝ E'' H''} {G'' : Type u_9} [TopologicalSpace G''] [ChartedSpace H'' G''] [Group G''] [LieGroup I'' (↑⊤) G''] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] [FiniteDimensional ℝ E''] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (ψ : ContMDiffMonoidMorphism I' I'' (↑⊤) G' G'') :
    lieMap (ψ.comp φ) = (lieMap ψ).comp (lieMap φ)

    The Lie map of a composite is the composite of the two Lie maps.

    @[simp]
    theorem map_lieExp {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (X : LeftInvariantDerivation I G) :
    have x := ⋯; have x_1 := ⋯; φ (lieExp X) = lieExp ((lieMap φ) X)

    A smooth group homomorphism intertwines the Lie-group exponentials through its Lie map.

    theorem continuous_lieMap {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] [T2Space G] [T2Space G'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') :

    The Lie map of a smooth homomorphism is continuous, being a linear map between finite-dimensional real normed spaces.

    theorem ContMDiffMonoidMorphism.lieMap_injective_of_mfderiv_injective {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : Function.Injective ⇑(mfderiv% ⇑φ 1)) :

    A smooth homomorphism whose differential at the identity is injective induces an injective Lie-algebra homomorphism.

    theorem ContMDiffMonoidMorphism.lieMap_bijective_of_isLocalDiffeomorphAt {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) :

    The Lie map of a smooth homomorphism that is a local diffeomorphism at the identity is bijective: under evaluation at the identity it is the differential there, a linear equivalence.

    theorem ContMDiffMonoidMorphism.isLocalDiffeomorphAt_of_lieMap_bijective {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : Function.Bijective ⇑(lieMap φ)) :
    IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1

    A smooth homomorphism with bijective Lie map is a local diffeomorphism at the identity.

    A smooth homomorphism of finite-dimensional Lie groups is a local diffeomorphism at the identity if and only if its Lie map is bijective.

    A smooth homomorphism of finite-dimensional Lie groups is a local diffeomorphism if and only if its Lie map is bijective.

    A smooth homomorphism with bijective Lie map is a local diffeomorphism.

    noncomputable def TauCeti.Lie.lieEquivOfIsLocalDiffeomorphAt {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) :

    A smooth homomorphism that is a local diffeomorphism at the identity induces an equivalence of Lie algebras.

    Instances For
      @[simp]
      theorem TauCeti.Lie.lieEquivOfIsLocalDiffeomorphAt_apply {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) (X : LeftInvariantDerivation I G) :

      The Lie-algebra equivalence induced by a local diffeomorphism acts by the Lie functor.

      @[simp]
      theorem TauCeti.Lie.lieEquivOfIsLocalDiffeomorphAt_toLieHom {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) :

      The Lie homomorphism underlying the equivalence induced by a local diffeomorphism is its Lie map.

      @[simp]
      theorem TauCeti.Lie.lieEquivOfIsLocalDiffeomorphAt_symm_apply_lieMap {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) (X : LeftInvariantDerivation I G) :

      The inverse Lie-algebra equivalence of a local diffeomorphism sends the Lie map of a derivation back to that derivation.

      @[simp]
      theorem TauCeti.Lie.lieMap_lieEquivOfIsLocalDiffeomorphAt_symm_apply {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℝ E] {H : Type u_2} [TopologicalSpace H] {I : ModelWithCorners ℝ E H} {G : Type u_3} [TopologicalSpace G] [ChartedSpace H G] [Group G] {E' : Type u_4} [NormedAddCommGroup E'] [NormedSpace ℝ E'] {H' : Type u_5} [TopologicalSpace H'] {I' : ModelWithCorners ℝ E' H'} {G' : Type u_6} [TopologicalSpace G'] [ChartedSpace H' G'] [Group G'] [LieGroup I (↑⊤) G] [LieGroup I' (↑⊤) G'] [FiniteDimensional ℝ E] [FiniteDimensional ℝ E'] (φ : ContMDiffMonoidMorphism I I' (↑⊤) G G') (hφ : IsLocalDiffeomorphAt I I' (↑⊤) (⇑φ) 1) (Y : LeftInvariantDerivation I' G') :

      The Lie map of a local diffeomorphism sends the inverse Lie-algebra equivalence of a derivation back to that derivation.