Contractible subgraphs and Morita equivalence of graph C*-algebras

Abstract

In this paper we describe an operation on directed graphs which produces a graph with fewer vertices, such that the C*-algebra of the new graph is Morita equivalent to that of the original graph. We unify and generalize several related constructions, notably delays and desingularizations of directed graphs.

arXiv comment10 pages, uses XY-pic v3.7