English

Computing K-theory and Ext for graph C*-algebras

Operator Algebras 2007-05-23 v1

Abstract

K-theory and Ext are computed for the C*-algebra C*(E) of any countable directed graph E. The results generalize the K-theory computations of Raeburn and Szymanski and the Ext computations of Tomforde for row-finite graphs. As a consequence, it is shown that if A is a countable {0,1} matrix and E_A is the graph obtained by viewing A as a vertex matrix, then C*(E_A) is not necessarily Morita equivalent to the Exel-Laca algebra O_A.

Keywords

Cite

@article{arxiv.math/0103036,
  title  = {Computing K-theory and Ext for graph C*-algebras},
  author = {D. Drinen and M. Tomforde},
  journal= {arXiv preprint arXiv:math/0103036},
  year   = {2007}
}