The conjecture that all orientations of odd cycles are avoidable
The conjecture that all orientations of odd cycles are avoidable
A digraph is avoidable if there exists a function such that every digraph of minimum out-degree at least contains an -free subdigraph of minimum out-degree at least . An orientation of an odd cycle is a digraph obtained by assigning a direction to every edge of a cycle of odd length.
Odd-cycle avoidability conjecture. All orientations of odd cycles are avoidable.
The paper proves avoidability for all orientations of and , while showing that the most direct directed extension of Thomassen's conjecture is false. The conjecture remains open for odd cycles beyond the cases established in the paper.
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Sources & referencesView supporting material
Primary source
Micha Christoph, Barnabás Janzer, Kalina Petrova and Raphael Steiner, “Extending Thomassen's conjecture to directed graphs”, arXiv:2510.11311 (2025).
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