English

A new proof of the K\L R conjecture

Combinatorics 2021-08-13 v1

Abstract

Estimating the probability that the Erd\H{o}s-R\'enyi random graph G(n,m)G(n,m) is HH-free, for a fixed graph HH, is one of the fundamental problems in random graph theory. If mm is such that each edge of G(n,m)G(n,m) belongs to a copy of HH' for every HHH' \subseteq H, in expectation, then it is known that G(n,m)G(n,m) is HH-free with probability exp(Θ(m))\exp(- \Theta(m)). The KLR conjecture, slightly rephrased, states that if we further condition on uniform edge distribution, the archetypal property of random graphs, the probability of being HH-free becomes superexponentially small in the number of edges. While being interesting on its own, the conjecture has received significant attention due to its connection with the sparse regularity lemma, and the many results in random graphs that follow. It was proven by Balogh, Morris, and Samotij and, independently, by Saxton and Thomason, as one of the first applications of the hypergraph containers method. We give a new direct proof using induction.

Keywords

Cite

@article{arxiv.2108.05687,
  title  = {A new proof of the K\L R conjecture},
  author = {Rajko Nenadov},
  journal= {arXiv preprint arXiv:2108.05687},
  year   = {2021}
}

Comments

Comments are welcome!