Finite simple labeled graph $C^{\ast }$-algebras of Cantor minimal subshifts

Abstract

It is now well known that a simple graph $C^{\ast }$-algebra $C^{\ast }(E)$ of a directed graph $E$ is either AF or purely infinite. In this paper, we address the question of whether this is the case for labeled graph $C^{\ast }$-algebras recently introduced by Bates and Pask as one of the generalizations of graph $C^{\ast }$-algebras, and show that there exists a family of simple unital labeled graph $C^{\ast }$-algebras which are neither AF nor purely infinite. Actually these algebras are shown to be isomorphic to crossed products $C(X){\times }_T\mathbb{Z}$ where the dynamical systems $(X,T)$ are Cantor minimal subshifts. Then it is an immediate consequence of well known results about this type of crossed products that each labeled graph $C^{\ast }$-algebra in the family obtained here is an $A\mathbb{T}$ algebra with real rank zero and has $\mathbb{Z}$ as its $K_1$-group.

arXiv comment18 pages