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Strongly Projective Graphs

Published online by Cambridge University Press:  20 November 2018

Benoit Larose*
Affiliation:
Department of Mathematics, Champlain Regional College, 900 Riverside St-Lambert, Quebec, J4P 3P2 Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve West Montréal, Quebec, H3G 1M8, e-mail: [email protected]
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Abstract

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We introduce the notion of strongly projective graph, and characterise these graphs in terms of their neighbourhood poset. We describe certain exponential graphs associated to complete graphs and odd cycles. We extend and generalise a result of Greenwell and Lovász [6]: if a connected graph $G$ does not admit a homomorphism to $K$, where $K$ is an odd cycle or a complete graph on at least 3 vertices, then the graph $G\,\times \,{{K}^{S}}$ admits, up to automorphisms of $K$, exactly $s$ homomorphisms to $K$.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2002

References

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