Abstract:
The relationship between graph coloring and the immersion order is considered. Vertex connectivity, edge connectivity and related issues are explored. These lead to the conjecture that, if G requires at least t colors, then G must have immersed within it Kt, the complete graph on t vertices. Evidence in support of such a proposition is presented. For each fixed value of t, there can be only a finite number of minimal counterexamples. These counterexamples are characterized based on Kempe chains, connectivity, cutsets and degree bounds. It is proved that minimal counterexamples must, if any exist, be both 4-vertex-connected and t-edge-connected.
Citation:
Abu-Khzam, F. N., & Langston, M. A. (2003, July). Graph coloring and the immersion order. In International Computing and Combinatorics Conference (pp. 394-403). Springer Berlin Heidelberg.