Abstract
An important theorem of Gross and Tucker characterises a directed graph $E$ which admits a free action of a group as a skew product. Here we extend this to directed graphs admitting free actions of semigroups, $S$, under certain hypotheses. Indeed, the main criterion we employ can be completely characterised by properties of the quotient map $E \rightarrow E/S$.
Information
Published: 1 January 1999
First available in Project Euclid: 18 November 2014
zbMATH: 1193.05068
Rights: Copyright © 1999, Centre for Mathematics and its Applications, Mathematical Sciences Institute, The Australian National University. This book is copyright. Apart from any fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act, no part may be reproduced by any process without permission. Inquiries should be made to the publisher.