On Cocircuit Graphs

EJ. Farrell1, J. Grell1
1Department of Mathematics The University of West Indies St. Augustine, Trinidad

Abstract

It is shown that the circuit polynomial of a graph, when weighted by the number of nodes in the circuits, does not characterize the graph, i.e., non-isomorphic graphs can have the same circuit polynomial. Some general theorems are given for constructing graphs with the same circuit polynomial (cocircuit graphs). Analogous results can be deduced for characteristic polynomials.