Continuous cyclic and mixed cochain operators #
The Hochschild and cyclic operators preserve jointly continuous multilinear cochains on a
topological algebra. This file lifts the algebraic operators to native
ContinuousMultilinearMaps and proves the mixed-complex identities there. The comparison
with algebraic cochains is given by the forgetful map toMultilinearMap, and on cyclic
cochains by continuousCyclicCochains.toCyclicCochains. Preservation of cyclic cochains does
not require associativity; the Hochschild and bar square-zero identities do. Continuous cyclic
cochains pull back along continuous linear maps (continuousCyclicCochainsMap), functorially,
and compatibly with the Hochschild coboundary along continuous homomorphisms of nonunital algebras.
No norm, local convexity, completeness or separation is needed for preservation of continuity.
The scalar action on the target is continuous for each fixed scalar. For a unital algebra,
insertion of the unit gives the continuous bar contraction and hence Connes' operator B.
These operations supply the differentials for continuous cyclic cohomology, including on
Fréchet algebras. No topology on the space of cochains or quotient cohomology is imposed here.
References #
- A. Connes, Noncommutative Geometry, Chapter III, §1.
- J.-L. Loday, Cyclic Homology, §§1.1, 2.1.
The algebraic formulas and identities are those of
TauCeti.RingTheory.CyclicCohomology.ConnesOperator.
Multiplication faces of tuples are continuous for a jointly continuous multiplication.
Cyclic permutation with its sign preserves joint continuity.
The finite cyclic norm preserves joint continuity.
Every Hochschild coface preserves joint continuity.
The Hochschild coboundary preserves joint continuity.
The bar coboundary preserves joint continuity.
Inserting the unit as the first argument preserves joint continuity.
Connes' operator preserves joint continuity.
The signed cyclic rotation on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic cyclic rotation.
Evaluation of the continuous cyclic rotation agrees with the algebraic formula.
The cyclic norm on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic cyclic norm.
Evaluation of the continuous cyclic norm agrees with the algebraic formula.
The Hochschild coboundary on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic Hochschild coboundary.
Evaluation of the continuous Hochschild coboundary agrees with the algebraic formula.
The bar coboundary on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic bar coboundary.
Evaluation of the continuous bar coboundary agrees with the algebraic formula.
The unit-inserting contraction on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic unit-inserting contraction.
Evaluation of the continuous unit insertion agrees with the algebraic formula.
Connes' operator on continuous multilinear cochains.
Instances For
Forgetting continuity recovers the algebraic Connes operator.
Evaluation of the continuous Connes operator agrees with the algebraic formula.
The submodule of jointly continuous cochains satisfying the signed cyclic relation.
Instances For
A continuous cochain is cyclic precisely when its underlying algebraic cochain is cyclic.
The cyclic norm of a continuous cochain is cyclic.
Connes' operator takes continuous cochains to continuous cyclic cochains.
Connes' operator vanishes on continuous cyclic cochains.
The continuous Connes operator squares to zero.
The Hochschild coboundary preserves continuous cyclic cochains.
The Hochschild coboundary restricted to continuous cyclic cochains.
Instances For
The restricted coboundary agrees with the continuous Hochschild coboundary.
The continuous Hochschild coboundary squares to zero.
The continuous bar coboundary squares to zero.
The restricted continuous cyclic differential squares to zero.
In degree zero, insertion of the unit contracts the continuous bar differential.
In positive degrees, insertion of the unit contracts the continuous bar differential.
The continuous Hochschild and Connes operators anticommute.
Forgetting continuity, as a linear map from continuous cyclic cochains to cyclic cochains.
Instances For
Forgetting continuity keeps the underlying multilinear map.
Forgetting continuity is injective.
Forgetting continuity commutes with the Hochschild coboundary.
The pullback φ ↦ φ ∘ (f × ⋯ × f) of continuous cyclic cochains along a continuous linear
map.
Instances For
The pullback of a continuous cyclic cochain evaluates it on the images of the arguments.
Forgetting continuity commutes with pullback.
Pulling back along the identity is the identity.
Pulling back along a composite is the composite of the pullbacks, in the opposite order.
Pulling continuous cyclic cochains back along a continuous homomorphism of nonunital algebras commutes with the Hochschild coboundary.