Algebras, graphs and thetas
Combinatorics
2019-10-15 v1
Abstract
We extend the clique-coclique inequality, previously known to hold for graphs in association schemes and vertex-transitive graphs, to graphs in homogeneous coherent configurations and 1-walk regular graphs. We further generalize it to a stronger inequality involving the Lov\'asz theta number of such graphs, and some theta variants, including characterizations of the equality.
Cite
@article{arxiv.1910.06260,
title = {Algebras, graphs and thetas},
author = {Marcel K. de Carli Silva and Gabriel Coutinho and Chris Godsil and David E. Roberson},
journal= {arXiv preprint arXiv:1910.06260},
year = {2019}
}
Comments
A version of this paper is published on the proceedings of LAGOS 2019