English

Proof of the KAMAK tree conjecture

Combinatorics 2025-05-28 v1

Abstract

There are many intriguing questions in extremal graph theory that are well-understood in the undirected setting and yet remain elusive for digraphs. A natural instance of such a problem was recently studied by Hons, Klimo\v{s}ov\'{a}, Kucheriya, Mik\v{s}an\'{i}k, Tkadlec and Tyomkyn: What are the digraphs that have to appear as a subgraph in all digraphs of sufficiently large minimum out-degree? Hons et al. showed that all such digraphs must be oriented forests with a specific structure, and conjectured that vice-versa all oriented forests with this specific structure appear in any digraph of sufficiently large minimum out-degree. In this paper, we confirm their conjecture.

Keywords

Cite

@article{arxiv.2505.21367,
  title  = {Proof of the KAMAK tree conjecture},
  author = {Micha Christoph and Raphael Steiner},
  journal= {arXiv preprint arXiv:2505.21367},
  year   = {2025}
}

Comments

12 pages

R2 v1 2026-07-01T02:43:32.280Z