The “characteristic” of a graph—the number of vertices, minus the number of edges, plus the number of triangles, etc.—is a little-studied, overtly combinatorial graph parameter intrinsically related to chordal graphs and common neighborhoods of subgraphs. I also introduce a sequence of related “higher characteristic” parameters.
Citation
Terry A.McKee. Characteristic Parameters, Chordal Graphs, and Common Neighborhoods[J], Journal of Combinatorial Mathematics and Combinatorial Computing, Volume 024. 155-159. .