English

Ext classes and embeddings for C*-algebras of graphs with sinks

Operator Algebras 2007-05-23 v2

Abstract

We consider directed graphs E which have been obtained by adding a sink to a fixed graph G. We associate an element of Ext(C*(G)) to each such E, and show that the classes of two such graphs are equal in Ext(C*(G)) if and only if the associated C*-algebra of one can be embedded as a full corner in the C*-algebra of the other in a particular way. If every loop in G has an exit, then we are able to use this result to generalize some of the classification theorems of Raeburn, Tomforde, and Williams for C*-algebras of graphs with sinks.

Keywords

Cite

@article{arxiv.math/0103056,
  title  = {Ext classes and embeddings for C*-algebras of graphs with sinks},
  author = {Mark Tomforde},
  journal= {arXiv preprint arXiv:math/0103056},
  year   = {2007}
}

Comments

24 pages, uses XY-pic, New version comments: small typos fixed, to appear in New York J. Math

R2 v1 2026-07-22T16:37:38.687Z