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arXiv · 2505.21367

Proof of the KAMAK tree conjecture

Micha Christoph·Raphael Steiner
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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.

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Micha Christoph, Raphael Steiner. 2025-05-27. Proof of the KAMAK tree conjecture. https://arxiv.org/abs/2505.21367

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