Near inclusions of amenable operator algebras

phi-Amenable and phi-biflat Banach algebras

In this paper we study the concept of ph-biatness ofa Banach algebra A, where ph is a continuous homomorphism on A.We prove that if ph is a continuous epimorphism on A and A hasa bounded approximate identity and A is ph- biat, then A is ph-amenable. In the case where ph is an isomorphism on A we showthat the ph- amenability of A implies its ph-biatness.

Ergodic Theoretic Characterization of Left Amenable Lau Algebras

CHARACTERIZATIONS OF EXTREMELY AMENABLE FUNCTION ALGEBRAS ON A SEMIGROUP

Let S be a semigroup. In certain cases we give some characterizations of extreme amenability of S and we show that in these cases extreme left amenability and extreme right amenability of S are equivalent. Also when S is a compact topological semigroup, we characterize extremely left amenable subalgebras of C(S), where C(S) is the space of all continuous bounded real valued functions on S

Some Extremely Amenable Groups Related to Operator Algebras and Ergodic Theory

A topological group G is called extremely amenable if every continuous action of G on a compact space has a fixed point. This concept is linked with geometry of high dimensions (concentration of measure). We show that a von Neumann algebra is approximately finite-dimensional if and only if its unitary group with the strong topology is the product of an extremely amenable group with a compact gr...

Inclusions of Simple C-algebras

We prove that if a conditional expectation from a simple C∗-algebra onto its C∗-subalgebra satisfies the Pimsner-Popa inequality, there exists a quasibasis. As an application, we establish the Galois correspondence for outer actions of finite groups (and more generally finite dimensional Kac algebras) on simple C∗algebras. We also introduce the notion of sectors for stable simple C∗-algebras an...