English

Optimal bisections of directed graphs

Combinatorics 2023-02-09 v1

Abstract

In this paper, motivated by a problem of Scott and a conjecture of Lee, Loh and Sudakov we consider bisections of directed graphs. We prove that every directed graph with mm arcs and minimum semidegree at least dd admits a bisection in which at least (d2(2d+1)+o(1))m\left(\frac{d}{2(2d+1)}+o(1)\right)m arcs cross in each direction. This provides an optimal bound as well as a positive answer to a question of Hou and Wu in a stronger form.

Keywords

Cite

@article{arxiv.2302.04050,
  title  = {Optimal bisections of directed graphs},
  author = {Guanwu Liu and Jie Ma and Chunlei Zu},
  journal= {arXiv preprint arXiv:2302.04050},
  year   = {2023}
}
R2 v1 2026-06-28T08:35:01.699Z