English

A hypergraph analog of Dirac's Theorem for long cycles in 2-connected graphs, II: Large uniformities

Combinatorics 2023-10-23 v1

Abstract

Dirac proved that each nn-vertex 22-connected graph with minimum degree kk contains a cycle of length at least min{2k,n}\min\{2k, n\}. We obtain analogous results for Berge cycles in hypergraphs. Recently, the authors proved an exact lower bound on the minimum degree ensuring a Berge cycle of length at least min{2k,n}\min\{2k, n\} in nn-vertex rr-uniform 22-connected hypergraphs when kr+2k \geq r+2. In this paper we address the case kr+1k \leq r+1 in which the bounds have a different behavior. We prove that each nn-vertex rr-uniform 22-connected hypergraph HH with minimum degree kk contains a Berge cycle of length at least min{2k,n,E(H)}\min\{2k,n,|E(H)|\}. If E(H)n|E(H)|\geq n, this bound coincides with the bound of the Dirac's Theorem for 2-connected graphs.

Keywords

Cite

@article{arxiv.2310.13190,
  title  = {A hypergraph analog of Dirac's Theorem for long cycles in 2-connected graphs, II: Large uniformities},
  author = {Alexandr Kostochka and Ruth Luo and Grace McCourt},
  journal= {arXiv preprint arXiv:2310.13190},
  year   = {2023}
}

Comments

23 pages, 1 figure. arXiv admin note: text overlap with arXiv:2212.14516