OAI/Analysis/KadisonKastler/InjectiveStability.lean

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Strong stability when the source algebra is injective

The one-sided amenable embedding gives a nearby conjugate subalgebra of the neighbor. Riesz's lemma forces this inclusion to be equality once the unit-ball gap is below one. No second perturbation or injectivity of the neighbor is required.

  1. theorem OAI.KadisonKastler.eq_of_le_of_kkDistance_lt_one line 26

    Source documentation

    A proper closed linear subspace cannot approximate the entire unit ball with uniform error less than one. Applied inside the larger algebra, this turns a sufficiently close inclusion into equality.

    theorem eq_of_le_of_kkDistance_lt_one {P Q : VonNeumannAlgebra H}
        (hPQ : P ≤ Q) (hgap : kkDistance P Q < 1) : P = Q := by
    …

    Mentions: OAI.KadisonKastler.kkDistance

  2. theorem OAI.KadisonKastler.exists_injective_conjugacy_of_kkDistance_lt line 52

    Source documentation

    The one-sided embedding already gives equality for an injective source at a sufficiently small ordinary distance.

    theorem exists_injective_conjugacy_of_kkDistance_lt
        (hpub : PublishedAmenableEmbedding (H := H))
    …

    Mentions: OAI.KadisonKastler.PublishedAmenableEmbedding

  3. theorem OAI.KadisonKastler.uniform_injective_strong_stability line 73

    Source documentation

    The tolerance is independent of the Hilbert space and the two algebras. Only the source must be injective.

    theorem uniform_injective_strong_stability {ε : ℝ} (hε : 0 < ε) :
        ∃ δ : ℝ, 0 < δ ∧
          ∀ (H : Type u) [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H],
          PublishedAmenableEmbedding (H := H) →
    …

    Mentions: OAI.KadisonKastler.PublishedAmenableEmbedding