Abstract
In 1981, Bermond and Thomassen conjectured that for any positive integer k, every digraph with minimum out-degree at least 2k−1 admits k vertex-disjoint directed cycles. In this short paper, we verify the Bermond-Thomassen conjecture for triangle-free multipartite tournaments and 3-partite tournaments. Furthermore, we characterize 3-partite tournaments with minimum out-degree at least 2k−1 (k≥2) such that in each set of k vertex-disjoint directed cycles, every cycle has the same length.
Original language | English |
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Article number | 114126 |
Journal | Discrete Mathematics |
Volume | 347 |
Issue number | 10 |
Number of pages | 5 |
ISSN | 0012-365X |
DOIs | |
Publication status | Published - Oct 2024 |
Keywords
- Bermond-Thomassen conjecture
- Disjoint cycles
- Minimum out-degree
- Multipartite tournaments