English

Random cliques in random graphs revisited

Combinatorics 2025-04-02 v1 Probability

Abstract

We study the distribution of the set of copies of some given graph HH in the random graph G(n,p)G(n,p), focusing on the case when H=KrH = K_r. Our main results capture the 'leading term' in the difference between this distribution and the 'independent hypergraph model', where (in the case H=KrH = K_r) each copy is present independently with probability π=p(r2)\pi = p^{\binom{r}{2}}. As a concrete application, we derive a new upper bound on the number of KrK_r-factors in G(n,p)G(n,p) above the threshold for such factors to appear. We will prove our main results in a much more general setting, so that they also apply to random hypergraphs, and also (for example) to the case when pp is constant and r=r(n)2log1/p(n)r = r(n) \sim 2\log_{1/p}(n).

Keywords

Cite

@article{arxiv.2504.00964,
  title  = {Random cliques in random graphs revisited},
  author = {Robert Morris and Oliver Riordan},
  journal= {arXiv preprint arXiv:2504.00964},
  year   = {2025}
}

Comments

51 pages

R2 v1 2026-06-28T22:42:41.619Z