The Relative (Co)homology Theory through Operator Algebras

Relative Cohomology of Banach Algebras

Let A be a Banach algebra, not necessarily unital, and let B be a closed subalgebra of A. We establish a connection between the Banach cyclic cohomology group HC(A) of A and the Banach B-relative cyclic cohomology group HCnB(A) of A. We prove that, for a Banach algebra A with a bounded approximate identity and an amenable closed subalgebra B of A, up to topological isomorphism, HC(A) = HCnB(A) ...

Operator Theory and Operator Algebras

Multiplicity Theory for Operator Algebras.

I Since (3.1) is homogeneous of degree zero in vm, vm, and am in (3.2) can be taken to be dym/dy4, d2y/(dy4)2,resp. Thenv4 = 1 a4= 0 10 On the nullspheres (X = 0) one gets If = 0, where R = 0-i.e., just the Coulomb infinity. 11 E.g., X acts like a sort of gauge, or numerical length assigned to some standard physical rod by the observer at xm. This rod can be assigned any positive value, but not...

Relative annihilators and relative commutants in non-selfadjoint operator algebras

We extend von Neumann’s Double Commutant Theorem to the setting of nonselfadjoint operator algebras A, while restricting the notion of commutants of a subset S of A to those operators in A which commute with every operator in S. If A is a completely distributive commutative subspace lattice algebra acting on a Hilbert space H, we obtain an alternate characterization (to those of Erdos–Power and...

On the Homology Theory of Operator Algebras

For given Banach algebras A and B, we define a free resolution of algebraB over a homomorphism f : A → B and study some properties of the relative cyclic homology.