Article ID Journal Published Year Pages File Type
4653115 Electronic Notes in Discrete Mathematics 2006 6 Pages PDF
Abstract

An edge of a 5-connected graph is said to be contractible if the contraction of the edge results in a 5-connected graph. A 5-connected graph with no contractible edge is said to be contraction critically 5-connected. Let G be a contraction critically 5-connected graph and let H be a component of the subgraph induced by the set of degree 5 vertices of G. Then it is known that |V(H)|⩾4. We prove that if |V(H)|=4, then , where stands for the graph obtained from K4 by deleting one edge. Moreover, we show that either |NG(V(H))|=5 or |NG(V(H))|=6 and around H there is one of two specified structures called a -configuration and a split -configuration.

Related Topics
Physical Sciences and Engineering Mathematics Discrete Mathematics and Combinatorics