Excluding hooks and their complements
Combinatorics
2015-08-06 v2
Abstract
The celebrated Erdos-Hajnal conjecture states that for every -vertex undirected graph there exists such that every graph that does not contain as an induced subgraph contains a clique or an independent set of size at least . A weaker version of the conjecture states that the polynomial-size clique/independent set phenomenon occurs if one excludes both and its complement . We show that the weaker conjecture holds if is any path with a pendant edge at its third vertex; thus we give a new infinite family of graphs for which the conjecture holds.
Cite
@article{arxiv.1508.00634,
title = {Excluding hooks and their complements},
author = {Krzysztof Choromanski and Dvir Falik and Anita Liebenau and Viresh Patel and Marcin Pilipczuk},
journal= {arXiv preprint arXiv:1508.00634},
year = {2015}
}