OAI/Analysis/KadisonSimilarity/Tracial/ProjectionJoinTrace.lean

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5 declarations, 0 contain sorry, 0 declared as axioms

Finite joins of projections and their trace bound. These elementary support identities are used to control countable unions of small spectral projections in the normal representation argument.

  1. theorem OAI.KadisonSimilarity.trace_projection_le line 22

    Source documentation

    A positive trace is monotone in the algebraic projection order.

    theorem trace_projection_le {A : Type*} [CStarAlgebra A]
        [PartialOrder A] [StarOrderedRing A] (τ : A →ₚ[ℂ] ℂ)
        (p q : A) (hp : IsStarProjection p) (hq : IsStarProjection q)
        (h : q * p = p) : (τ p).re ≤ (τ q).re := by
    …
  2. theorem OAI.KadisonSimilarity.trace_normalRangeSupport_le line 31

    Source documentation

    The range support has trace at most that of a prescribed right support.

    theorem trace_normalRangeSupport_le (M : VonNeumannAlgebra H)
        (τ : M.toStarSubalgebra →ₚ[ℂ] ℂ)
        (htr : ∀ a b, τ (a * b) = τ (b * a))
        (x p : M.toStarSubalgebra) (hp : IsStarProjection p) (hxp : x * p = x) :
        (τ (normalRangeSupport M x)).re ≤ (τ p).re := by
    …

    Mentions: OAI.KadisonSimilarity.normalRangeSupport

  3. def OAI.KadisonSimilarity.projectionJoin line 45

    Source documentation

    Join formed from the orthogonal part of the second projection.

    def projectionJoin (M : VonNeumannAlgebra H) (p q : M.toStarSubalgebra) :
        M.toStarSubalgebra := p + normalRangeSupport M ((1 - p) * q)

    Mentions: OAI.KadisonSimilarity.normalRangeSupport

  4. theorem OAI.KadisonSimilarity.projectionJoin_properties line 48
  5. theorem OAI.KadisonSimilarity.trace_projectionJoin_le line 89

    Source documentation

    Subadditivity of the trace for a finite projection join.

    theorem trace_projectionJoin_le (M : VonNeumannAlgebra H)
        (τ : M.toStarSubalgebra →ₚ[ℂ] ℂ)
        (htr : ∀ a b, τ (a * b) = τ (b * a))
        (p q : M.toStarSubalgebra) (hq : IsStarProjection q) :
        (τ (projectionJoin M p q)).re ≤ (τ p).re + (τ q).re := by
    …

    Mentions: OAI.KadisonSimilarity.projectionJoin