A Characterization of Well Covered Graphs of Girth 5 or Greater

Abstract

A graph is well covered if every maximal independent set has the same cardinality. A vertex x, in a well covered graph G, is called extendable if G - {x} is well covered and β(G) = β(G - {x}). If G is a connected, well covered graph of girth ≥ 5 and G contains an extendable vertex then G is the disjoint union of edges and 5-cycles together with a restricted set of edges joining these subgraphs. There are only six connected, well covered graphs of girth ≥ 5 which do not contain an extendable vertex. © 1993 Academic Press. All rights reserved.