OAI/Analysis/KadisonSimilarity/Representation/UnitalizedExtension.lean

GitHub source file

7 declarations, 0 contain sorry, 0 declared as axioms

Extension by zero is a nonunital star homomorphism. Its unitization provides a genuine representation whose distinguished projection recovers the original Hilbert subspace.

  1. def OAI.KadisonSimilarity.isometricExtensionHom line 18
  2. theorem OAI.KadisonSimilarity.separable_unitization line 37
  3. def OAI.KadisonSimilarity.unitalizedExtension line 44

    Source documentation

    A unital representation retaining the zero extension of every original algebra element. The added unit acts on the full ambient Hilbert space.

    def unitalizedExtension : Unitization ℂ B →⋆ₐ[ℂ] (K →L[ℂ] K) :=
    …
  4. theorem OAI.KadisonSimilarity.unitalizedExtension_inr line 47
  5. theorem OAI.KadisonSimilarity.unitalizedExtension_apply line 52
  6. theorem OAI.KadisonSimilarity.unitalizedExtension_old_unit line 59

    Source documentation

    The old unit becomes the orthogonal range projection of the embedding.

    theorem unitalizedExtension_old_unit :
        unitalizedExtension J σ (Unitization.inr (1 : B)) =
          J.toContinuousLinearMap.comp J.toContinuousLinearMap.adjoint := by
    …

    Mentions: OAI.KadisonSimilarity.unitalizedExtension

  7. theorem OAI.KadisonSimilarity.unitalizedExtension_commutes line 65