English

An exact Ore-degree condition for Hamilton cycles in oriented graphs

Combinatorics 2025-07-08 v1

Abstract

An oriented graph is a digraph that contains no 2-cycles, i.e., there is at most one arc between any two vertices. We show that every oriented graph GG of sufficiently large order nn with deg+(x)+deg(y)(3n3)/4\mathrm{deg}^+(x) +\mathrm{deg}^{-}(y)\geq (3n-3)/4 whenever GG does not have an edge from xx to yy contains a Hamilton cycle. This is best possible and solves a problem of K\"uhn and Osthus from 2012. Our result generalizes the result of Keevash, K\"uhn, and Osthus and improves the asymptotic bound obtained by Kelly, K\"uhn, and Osthus.

Keywords

Cite

@article{arxiv.2507.04273,
  title  = {An exact Ore-degree condition for Hamilton cycles in oriented graphs},
  author = {Yulin Chang and Yangyang Cheng and Tianjiao Dai and Qiancheng Ouyang and Guanghui Wang},
  journal= {arXiv preprint arXiv:2507.04273},
  year   = {2025}
}
R2 v1 2026-07-01T03:48:07.868Z