OAI/Analysis/BoundedHochschild/AbelianPrimitives.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

Norm-one primitives on abelian von Neumann algebras

The abelian case of the classical type-I input is proved directly. Finite families of projections admit common finite partitions. Their separability homotopies have norm at most one; a bounded weak-* limit is exact on every projection, hence everywhere by density of the span of projections.

  1. lemma OAI.BoundedHochschild.KadisonRingrose.mergeInputs_cons_zero line 28
  2. lemma OAI.BoundedHochschild.KadisonRingrose.mergeInputs_cons_succ line 36
  3. lemma OAI.BoundedHochschild.KadisonRingrose.differentialValue_cons line 44
  4. lemma OAI.BoundedHochschild.KadisonRingrose.first_homotopy_identity line 69
  5. def OAI.BoundedHochschild.KadisonRingrose.partitionHomotopy line 85
  6. lemma OAI.BoundedHochschild.KadisonRingrose.partitionHomotopy_norm line 88
  7. lemma OAI.BoundedHochschild.KadisonRingrose.partitionHomotopy_exact line 109
  8. theorem OAI.BoundedHochschild.KadisonRingrose.abelian_primitive line 148

    Source documentation

    The abelian case of the classical input, proved with an explicit norm-one bound.

    theorem abelian_primitive (e : StrongDual ℂ X ≃ₗᵢ⋆[ℂ] M)
        {n : ℕ} (f : Cochain M (n + 1)) (hf : ∀ x, differentialValue f x = 0) :
        ∃ g : Cochain M n, ‖g‖ ≤ ‖f‖ ∧ ∀ x, differentialValue g x = f x := by
    …

    Mentions: OAI.BoundedHochschild.Cochain, OAI.BoundedHochschild.differentialValue