English

Degree versions of the Erdos-Ko-Rado Theorem and Erdos hypergraph matching conjecture

Combinatorics 2016-05-25 v1

Abstract

We use an algebraic method to prove a degree version of the celebrated Erd\H os-Ko-Rado theorem: given n>2kn>2k, every intersecting kk-uniform hypergraph HH on nn vertices contains a vertex that lies on at most (n2k2)\binom{n-2}{k-2} edges. This result can be viewed as a special case of the degree version of a well-known conjecture of Erd\H{o}s on hypergraph matchings. Improving the work of Bollob\'as, Daykin, and Erd\H os from 1976, we show that given integers n,k,sn, k, s with n3k2sn\ge 3k^2 s, every kk-uniform hypergraph HH on nn vertices with minimum vertex degree greater than (n1k1)(nsk1)\binom{n-1}{k-1}-\binom{n-s}{k-1} contains ss disjoint edges.

Keywords

Cite

@article{arxiv.1605.07535,
  title  = {Degree versions of the Erdos-Ko-Rado Theorem and Erdos hypergraph matching conjecture},
  author = {Hao Huang and Yi Zhao},
  journal= {arXiv preprint arXiv:1605.07535},
  year   = {2016}
}