English

Stability of extremal connected hypergraphs avoiding Berge-paths

Combinatorics 2023-09-26 v2

Abstract

A Berge-path of length kk in a hypergraph H\mathcal{H} is a sequence v1,e1,v2,e2,,vk,ek,vk+1v_1,e_1,v_2,e_2,\dots,v_{k},e_k,v_{k+1} of distinct vertices and hyperedges with vi,vi+1eiv_{i},v_{i+1} \in e_i, for iki \le k. F\"uredi, Kostochka and Luo, and independently Gy\H{o}ri, Salia and Zamora determined the maximum number of hyperedges in an nn-vertex, connected, rr-uniform hypergraph that does not contain a Berge-path of length kk provided kk is large enough compared to rr. They also determined the unique extremal hypergraph H1\mathcal{H}_1. We prove a stability version of this result by presenting another construction H2\mathcal{H}_2 and showing that any nn-vertex, connected, rr-uniform hypergraph without a Berge-path of length kk, that contains more than H2|\mathcal{H}_2| hyperedges must be a sub-hypergraph of the extremal hypergraph H1\mathcal{H}_1, provided kk is large enough compared to rr.

Keywords

Cite

@article{arxiv.2008.02780,
  title  = {Stability of extremal connected hypergraphs avoiding Berge-paths},
  author = {Dániel Gerbner and Dániel T. Nagy and Balázs Patkós and Nika Salia and Máté Vizer},
  journal= {arXiv preprint arXiv:2008.02780},
  year   = {2023}
}
R2 v1 2026-06-23T17:41:18.033Z