OAI/Analysis/KadisonSimilarity/FreeProduct/FreeWordExpectation.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

The base expectation kills every reduced word starting in the other free factor. This is derived from scalar freeness by trace tests.

  1. theorem OAI.KadisonSimilarity.TracialExpectation.map_reduced_word line 18

    Source documentation

    A reduced word beginning in the other factor has zero base expectation, including when its final letter belongs to the base algebra.

    theorem map_reduced_word (E : TracialExpectation τ A)
        (hfaithful : ∀ x, τ (star x * x) = 0 → x = 0)
        (hτ : τ 1 = 1) (hfree : ScalarFree τ D A)
        (x : P) (xs : List P) (hword : AlternatingCenteredWord τ D A true (x :: xs)) :
        E.map ((x :: xs).prod) = 0 := by
    …

    Mentions: OAI.KadisonSimilarity.TracialExpectation, OAI.KadisonSimilarity.ScalarFree, OAI.KadisonSimilarity.AlternatingCenteredWord

  2. theorem OAI.KadisonSimilarity.TracialExpectation.map_base_mul_reduced_word line 41

    Source documentation

    A base letter at the front of such a word is removed by bimodularity.

    theorem map_base_mul_reduced_word (E : TracialExpectation τ A)
        (hfaithful : ∀ x, τ (star x * x) = 0 → x = 0)
        (hτ : τ 1 = 1) (hfree : ScalarFree τ D A)
        (a : P) (ha : a ∈ A) (x : P) (xs : List P)
        (hword : AlternatingCenteredWord τ D A true (x :: xs)) :
        E.map (a * (x :: xs).prod) = 0 := by
    …

    Mentions: OAI.KadisonSimilarity.TracialExpectation, OAI.KadisonSimilarity.ScalarFree, OAI.KadisonSimilarity.AlternatingCenteredWord