English

On regular hypergraphs of high girth

Combinatorics 2017-07-14 v5

Abstract

We give lower bounds on the maximum possible girth of an rr-uniform, dd-regular hypergraph with at most nn vertices, using the definition of a hypergraph cycle due to Berge. These differ from the trivial upper bound by an absolute constant factor (viz., by a factor of between 3/2+o(1)3/2+o(1) and 2+o(1)2 +o(1)). We also define a random rr-uniform `Cayley' hypergraph on SnS_n which has girth Ω(n1/3)\Omega (n^{1/3}) with high probability, in contrast to random regular rr-uniform hypergraphs, which have constant girth with positive probability.

Keywords

Cite

@article{arxiv.1302.5090,
  title  = {On regular hypergraphs of high girth},
  author = {David Ellis and Nathan Linial},
  journal= {arXiv preprint arXiv:1302.5090},
  year   = {2017}
}

Comments

A hole in the proof of Theorem 8 was recently pointed out by Eberhard [10]. In this version, we repair the hole, giving a slightly weaker bound. We use a very similar method to that of Eberhard in [10], where a slightly weaker variant of [13, Theorem 3] is proved; our original proof contained a similar hole to the original proof of [13, Theorem 3]

R2 v1 2026-06-21T23:29:41.714Z