Chi-boundedness of graph classes excluding wheel vertex-minors
arXiv:1702.07851 · doi:10.1016/j.jctb.2018.08.009
Abstract
A class of graphs is -bounded if there exists a function such that for every graph in the class and an induced subgraph of , if has no clique of size , then the chromatic number of is less than or equal to . We denote by the wheel graph on vertices. We show that the class of graphs having no vertex-minor isomorphic to is -bounded. This generalizes several previous results; -boundedness for circle graphs, for graphs having no vertex-minors, and for graphs having no fan vertex-minors.
27 pages, 9 figures (revised version)