English

On The Random Tur\'an number of linear cycles

Combinatorics 2023-05-01 v1

Abstract

Given two rr-uniform hypergraphs GG and HH the Tur\'an number ex(G,H)\rm{ex}(G, H) is the maximum number of edges in an HH-free subgraph of GG. We study the typical value of ex(G,H)\rm{ex}(G, H) when G=Gn,p(r)G=G_{n,p}^{(r)}, the Erd\H{o}s-R\'enyi random rr-uniform hypergraph, and H=C2(r)H=C_{2\ell}^{(r)}, the rr-uniform linear cycle of length 22\ell. The case of graphs (r=2r=2) is a longstanding open problem that has been investigated by many researchers. We determine the order of magnitude of ex(Gn,p(r),C2(r))\rm{ex}\left(G_{n,p}^{(r)}, C_{2\ell}^{(r)}\right) for all r4r\geq 4 and all 2\ell\geq 2 up to polylogarithmic factors for all values of p=p(n)p=p(n). Our proof is based on the container method and uses a balanced supersaturation result for linear even cycles which improves upon previous such results by Ferber-Mckinley-Samotij and Balogh-Narayanan-Skokan.

Keywords

Cite

@article{arxiv.2304.15003,
  title  = {On The Random Tur\'an number of linear cycles},
  author = {Dhruv Mubayi and Liana Yepremyan},
  journal= {arXiv preprint arXiv:2304.15003},
  year   = {2023}
}

Comments

16 pages. arXiv admin note: substantial text overlap with arXiv:2007.10320