{ "id": "2311.13369", "version": "v1", "published": "2023-11-22T13:07:24.000Z", "updated": "2023-11-22T13:07:24.000Z", "title": "Note on Disjoint Cycles in Multipartite Tournaments", "authors": [ "Gregory Gutin", "Wei Li", "Shujing Wang", "Anders Yeo", "Yacong Zhou" ], "comment": "9 pages, 0 figure", "categories": [ "math.CO" ], "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 $2k-1$ ($k\\geq 2$) such that in each set of $k$ vertex-disjoint directed cycles, every cycle has the same length.", "revisions": [ { "version": "v1", "updated": "2023-11-22T13:07:24.000Z" } ], "analyses": { "subjects": [ "05C20", "05C75" ], "keywords": [ "disjoint cycles", "vertex-disjoint directed cycles", "minimum out-degree", "triangle-free multipartite tournaments", "bermond-thomassen conjecture" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable" } } }