English

Ramsey-Tur\'an numbers for intersecting odd cliques

Combinatorics 2020-09-15 v1

Abstract

Given a graph HH and a function f:Z+Z+f:\mathbb{Z}^+ \longrightarrow \mathbb{Z}^+ , the Ramsey-Tur\'an number of HH and ff, denoted by RT(n,H,f(n))RT(n, H, f(n)), is the maximum number of edges a graph GG on nn vertices can have, which does not contain HH as a subgraph and also does not contain a set of f(n)f(n) independent vertices. Let rr be a positive integer. In 1969, Erd\H{o}s and S\'os proved that RT(n,K2r+1,o(n))=n22(11r)+o(n2)RT(n,K_{2r+1},o(n))=\frac{n^2}{2}(1-\frac{1}{r})+o(n^2). Let Fk(2r+1)F_k(2r+1) denote the graph consisting of kk copies of complete graphs K2r+1K_{2r+1} sharing exactly one vertex. In this paper, we show that RT(n,Fk(2r+1),o(n))=n22(11r)+o(n2)RT(n,F_k(2r+1),o(n))=\frac{n^2}{2}(1-\frac{1}{r})+o(n^2), which is of the same magnitude with RT(n,K2r+1,o(n))RT(n, K_{2r+1}, o(n)).

Keywords

Cite

@article{arxiv.2009.06135,
  title  = {Ramsey-Tur\'an numbers for intersecting odd cliques},
  author = {Min Liu},
  journal= {arXiv preprint arXiv:2009.06135},
  year   = {2020}
}
R2 v1 2026-06-23T18:30:29.506Z