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Mathlib.Analysis.Normed.Operator.ContinuousAlgEquiv

Continuous (star-)algebra equivalences between continuous endomorphisms are (isometrically) inner #

This file shows that continuous (star-)algebra equivalences between continuous endomorphisms are (isometrically) inner. See Mathlib/LinearAlgebra/GeneralLinearGroup/AlgEquiv.lean for the non-continuous version. The proof follows the same idea as the non-continuous version.

TODO: #

theorem ContinuousAlgEquiv.eq_continuousLinearEquivConjContinuousAlgEquiv {๐•œ : Type u_1} {V : Type u_2} {W : Type u_3} [NontriviallyNormedField ๐•œ] [SeminormedAddCommGroup V] [SeminormedAddCommGroup W] [NormedSpace ๐•œ V] [NormedSpace ๐•œ W] [SeparatingDual ๐•œ V] [SeparatingDual ๐•œ W] (f : (V โ†’L[๐•œ] V) โ‰ƒA[๐•œ] W โ†’L[๐•œ] W) :
โˆƒ (U : V โ‰ƒL[๐•œ] W), f = U.conjContinuousAlgEquiv

This is the continuous version of AlgEquiv.eq_linearEquivConjAlgEquiv.

theorem StarAlgEquiv.eq_linearIsometryEquivConjStarAlgEquiv {๐•œ : Type u_1} {V : Type u_2} {W : Type u_3} [RCLike ๐•œ] [NormedAddCommGroup V] [InnerProductSpace ๐•œ V] [CompleteSpace V] [NormedAddCommGroup W] [InnerProductSpace ๐•œ W] [CompleteSpace W] (f : (V โ†’L[๐•œ] V) โ‰ƒโ‹†โ‚[๐•œ] W โ†’L[๐•œ] W) (hf : Continuous โ‡‘f) :
โˆƒ (U : V โ‰ƒโ‚—แตข[๐•œ] W), f = U.conjStarAlgEquiv

The โ‹†-algebra equivalence version of ContinuousAlgEquiv.eq_continuousLinearEquivConjContinuousAlgEquiv.

TODO: remove the hypothesis Continuous f, as star-algebra equivalences between endomorphisms are automatically continuous.

@[instance 100]
instance instOrderIsoClassContinuousLinearMapIdOfNonUnitalAlgEquivClassOfStarHomClassOfContinuousMapClass {๐•œ : Type u_1} {V : Type u_2} {W : Type u_3} [RCLike ๐•œ] [NormedAddCommGroup V] [InnerProductSpace ๐•œ V] [CompleteSpace V] [NormedAddCommGroup W] [InnerProductSpace ๐•œ W] [CompleteSpace W] {F : Type u_4} [EquivLike F (V โ†’L[๐•œ] V) (W โ†’L[๐•œ] W)] [NonUnitalAlgEquivClass F ๐•œ (V โ†’L[๐•œ] V) (W โ†’L[๐•œ] W)] [StarHomClass F (V โ†’L[๐•œ] V) (W โ†’L[๐•œ] W)] [ContinuousMapClass F (V โ†’L[๐•œ] V) (W โ†’L[๐•œ] W)] :
OrderIsoClass F (V โ†’L[๐•œ] V) (W โ†’L[๐•œ] W)