English

Ramsey-Tur\'an Problems with small independence numbers

Combinatorics 2023-08-04 v2

Abstract

Given a graph HH and a function f(n)f(n), the Ramsey-Tur\'an number RT(n,H,f(n))RT(n,H,f(n)) is the maximum number of edges in an nn-vertex HH-free graph with independence number at most f(n)f(n). For HH being a small clique, many results about RT(n,H,f(n))RT(n,H,f(n)) are known and we focus our attention on H=KsH=K_s for s13s\leq 13. By applying Szemer\'edi's Regularity Lemma, the dependent random choice method and some weighted Tur\'an-type results, we prove that these cliques have the so-called phase transitions when f(n)f(n) is around the inverse function of the off-diagonal Ramsey number of KrK_r versus a large clique KnK_n for some rsr\leq s.

Keywords

Cite

@article{arxiv.2207.10545,
  title  = {Ramsey-Tur\'an Problems with small independence numbers},
  author = {József Balogh and Ce Chen and Grace McCourt and Cassie Murley},
  journal= {arXiv preprint arXiv:2207.10545},
  year   = {2023}
}

Comments

20 pages

R2 v1 2026-06-25T01:07:16.126Z