English

Which graphs can be counted in $C_4$-free graphs?

Combinatorics 2021-06-08 v1

Abstract

For which graphs FF is there a sparse FF-counting lemma in C4C_4-free graphs? We are interested in identifying graphs FF with the property that, roughly speaking, if GG is an nn-vertex C4C_4-free graph with on the order of n3/2n^{3/2} edges, then the density of FF in GG, after a suitable normalization, is approximately at least the density of FF in an ϵ\epsilon-regular approximation of GG. In recent work, motivated by applications in extremal and additive combinatorics, we showed that C5C_5 has this property. Here we construct a family of graphs with the property.

Keywords

Cite

@article{arxiv.2106.03261,
  title  = {Which graphs can be counted in $C_4$-free graphs?},
  author = {David Conlon and Jacob Fox and Benny Sudakov and Yufei Zhao},
  journal= {arXiv preprint arXiv:2106.03261},
  year   = {2021}
}

Comments

13 pages

R2 v1 2026-06-24T02:53:29.174Z