English

Lower bounds on the Erd\H{o}s-Gy\'arf\'as problem via color energy graphs

Combinatorics 2022-05-26 v2

Abstract

Given positive integers pp and qq, a (p,q)(p,q)-coloring of the complete graph KnK_n is an edge-coloring in which every pp-clique receives at least qq colors. Erd\H{o}s and Shelah posed the question of determining f(n,p,q)f(n,p,q), the minimum number of colors needed for a (p,q)(p,q)-coloring of KnK_n. In this paper, we expand on the color energy technique introduced by Pohoata and Sheffer to prove new lower bounds on this function, making explicit the connection between bounds on extremal numbers and f(n,p,q)f(n,p,q). Using results on the extremal numbers of subdivided complete graphs, theta graphs, and subdivided complete bipartite graphs, we generalize results of Fish, Pohoata, and Sheffer, giving the first nontrivial lower bounds on f(n,p,q)f(n,p,q) for some pairs (p,q)(p,q) and improving previous lower bounds for other pairs.

Keywords

Cite

@article{arxiv.2102.11466,
  title  = {Lower bounds on the Erd\H{o}s-Gy\'arf\'as problem via color energy graphs},
  author = {József Balogh and Sean English and Emily Heath and Robert A. Krueger},
  journal= {arXiv preprint arXiv:2102.11466},
  year   = {2022}
}