English

On the probability of nonexistence in binomial subsets

Combinatorics 2019-04-18 v2 Probability

Abstract

Given a hypergraph Γ=(Ω,X)\Gamma=(\Omega,\mathcal{X}) and a sequence p=(pω)ωΩ\mathbf{p} = (p_\omega)_{\omega\in \Omega} of values in (0,1)(0,1), let Ωp\Omega_{\mathbf{p}} be the random subset of Ω\Omega obtained by keeping every vertex ω\omega independently with probability pωp_\omega. We investigate the general question of deriving fine (asymptotic) estimates for the probability that Ωp\Omega_{\mathbf{p}} is an independent set in Γ\Gamma, which is an omnipresent problem in probabilistic combinatorics. Our main result provides a sequence of upper and lower bounds on this probability, each of which can be evaluated explicitly in terms of the joint cumulants of small sets of edge indicator random variables. Under certain natural conditions, these upper and lower bounds coincide asymptotically, thus giving the precise asymptotics of the probability in question. We demonstrate the applicability of our results with two concrete examples: subgraph containment in random (hyper)graphs and arithmetic progressions in random subsets of the integers.

Keywords

Cite

@article{arxiv.1711.06216,
  title  = {On the probability of nonexistence in binomial subsets},
  author = {Frank Mousset and Andreas Noever and Konstantinos Panagiotou and Wojciech Samotij},
  journal= {arXiv preprint arXiv:1711.06216},
  year   = {2019}
}

Comments

28 pages

R2 v1 2026-06-22T22:48:31.245Z