English

Thresholds and expectation thresholds for larger p

Combinatorics 2026-01-19 v3 Probability

Abstract

Let pcp_\mathrm{c} and qcq_\mathrm{c} be the threshold and the expectation threshold, respectively, of an increasing family F\mathcal{F} of subsets of a finite set XX, and let ll be the size of a largest minimal element of F\mathcal{F}. Recently, Park and Pham proved the Kahn-Kalai conjecture, which says that pcKqclog2lp_\mathrm{c} \leqslant K q_\mathrm{c} \log_2 l for some universal constant KK. Here we slightly strengthen their result by showing that pc1eKqclog2lp_\mathrm{c} \leqslant 1 - \mathrm{e}^{-K q_\mathrm{c} \log_2 l}. The idea is to apply the Park-Pham Theorem to an appropriate `cloned' family Fk\mathcal{F}_k, reducing the general case (of this and related results) to the case where the individual element probability pp is small.

Keywords

Cite

@article{arxiv.2302.03327,
  title  = {Thresholds and expectation thresholds for larger p},
  author = {Tomasz Przybyłowski and Oliver Riordan},
  journal= {arXiv preprint arXiv:2302.03327},
  year   = {2026}
}

Comments

5 pages; minor edits; submitted

R2 v1 2026-06-28T08:33:52.064Z