English

On graphs with subgraphs of large independence numbers

Combinatorics 2007-06-29 v1

Abstract

Let G be a graph on n vertices in which every induced subgraph on s=\log^3 n vertices has an independent set of size at least t=\log n. What is the largest q=q(n) so that every such G must contain an independent set of size at least q ? This is one of several related questions raised by Erdos and Hajnal. We show that q(n)=\Theta(\log^2 n/\log \log n), investigate the more general problem obtained by changing the parameters s and t, and discuss the connection to a related Ramsey-type problem.

Keywords

Cite

@article{arxiv.0706.4099,
  title  = {On graphs with subgraphs of large independence numbers},
  author = {Noga Alon and Benny Sudakov},
  journal= {arXiv preprint arXiv:0706.4099},
  year   = {2007}
}