On exotic group C*-algebras

Autor: Zhong Jin Ruan, Matthew Wiersma
Rok vydání: 2015
Předmět:
DOI: 10.48550/arxiv.1505.00805
Popis: Let $\Gamma$ be a discrete group. A $C^*$-algebra $A$ is an exotic $C^*$-algebra (associated to $\Gamma$) if there exist proper surjective $C^*$-quotients $C^*(\Gamma)\to A\to C^*_r(\Gamma)$. In this paper, we show that a large class of exotic $C^*$-algebras have poor local properties. More precisely, we demonstrate the failure of local reflexitity, exactness, and local lifting property. Additionally, $A$ does not admit an amenable trace and, hence, is not quasidiagonal and does not have the WEP when $A$ is from the class of exotic $C^*$-algebras defined by Brown and Guentner. In order to achieve the main results of this paper, we prove a result which implies the factorization property for the class of discrete groups which are algebraic subgroups of locally compact amenable groups.
Comment: Improvements to some proofs and several other changes, 14 pages, to appear in J. Funct. Anal
Databáze: OpenAIRE