ArticleOriginal scientific text

Title

A cancellation property for the direct product of graphs

Authors 1

Affiliations

  1. Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA 23284-2014, USA

Abstract

Given graphs A, B and C for which A×C ≅ B×C, it is not generally true that A ≅ B. However, it is known that A×C ≅ B×C implies A ≅ B provided that C is non-bipartite, or that there are homomorphisms from A and B to C. This note proves an additional cancellation property. We show that if B and C are bipartite, then A×C ≅ B×C implies A ≅ B if and only if no component of B admits an involution that interchanges its partite sets.

Keywords

graph products, graph direct product, cancellation

Bibliography

  1. R. Hammack, A quasi cancellation property for the direct product, Proceedings of the Sixth Slovenian International Conference on Graph Theory, under review.
  2. P. Hell and J. Nesetril, Graphs and Homomorphisms, Oxford Lecture Series in Mathematics (Oxford U. Press, 2004), doi: 10.1093/acprof:oso/9780198528173.001.0001.
  3. W. Imrich and S. Klavžar, Product Graphs; Structure and Recognition (Wiley Interscience Series in Discrete Mathematics and Optimization, 2000).
  4. L. Lovász, On the cancellation law among finite relational structures, Period. Math. Hungar. 1 (1971) 59-101.
Pages:
179-184
Main language of publication
English
Received
2007-08-13
Accepted
2007-12-05
Published
2008
Exact and natural sciences