English

Finding long cycles in a percolated expander graphs

Combinatorics 2025-06-27 v2 Probability

Abstract

Given a graph GG, the percolated graph GpG_p has each edge independently retained with probability pp. Collares, Diskin, Erde, and Krivelevich initiated the study of large structures in percolated single-scale vertex expander graphs, wherein every set of exactly kk vertices of GG has at least dkdk neighbours before percolation. We extend their result to a conjectured stronger form, proving that if p=(1+ε)/dp = (1+\varepsilon)/d and GG is a graph on at least kk vertices which expands as above, then GpG_p contains a cycle of length Ωε(kd)\Omega_\varepsilon(kd) with probability at least 1exp(Ωε(k/d))1-\exp(-\Omega_\varepsilon(k/d)) as kk\rightarrow\infty.

Keywords

Cite

@article{arxiv.2506.12162,
  title  = {Finding long cycles in a percolated expander graphs},
  author = {Lawrence Hollom},
  journal= {arXiv preprint arXiv:2506.12162},
  year   = {2025}
}

Comments

11 pages

R2 v1 2026-07-01T03:16:55.978Z