On Plick Graphs with Point-outercoarseness Number One

Abstract

The plick graph P(G) of a graph G is obtained from the line graph by adding a new vertex corresponding to each block of the original graph and joining this vertex to the vertices of the line graph which correspond to the edges of the block of the original graph. The point outer-coarseness is the maximum number of vertex-disjoint nonouterplanar subgraphs of G. In this paper, we obtain a necessary and sufficient conditions for the plick graph P(G) to have pointoutercoarseness number one.