{ "id": "1707.03600", "version": "v1", "published": "2017-07-12T08:53:06.000Z", "updated": "2017-07-12T08:53:06.000Z", "title": "On splitting digraphs", "authors": [ "Donglei Yang", "Yandong Bai", "Guanghui Wang", "Jianliang Wu" ], "comment": "8 pages, 0 figures", "categories": [ "math.CO" ], "abstract": "In 1995, Stiebitz asked the following question: For any positive integers $s,t$, is there a finite integer $f(s,t)$ such that every digraph $D$ with minimum out-degree at least $f(s,t)$ admits a bipartition $(A, B)$ such that $A$ induces a subdigraph with minimum out-degree at least $s$ and $B$ induces a subdigraph with minimum out-degree at least $t$? We give an affirmative answer for tournaments, bipartite tournaments, multipartite tournaments, and digraphs with bounded maximum in-degrees. In particular, we show that for every $0<\\epsilon<\\frac{1}{4}$, there exists an integer $\\delta_0$ such that every tournament with minimum out-degree at least $\\delta_0$ admits a bisection $(A, B)$, so that each vertex has at least $(\\frac{1}{4}-\\epsilon)$ of its out-neighbors in $A$, and in $B$ as well.", "revisions": [ { "version": "v1", "updated": "2017-07-12T08:53:06.000Z" } ], "analyses": { "keywords": [ "minimum out-degree", "splitting digraphs", "subdigraph", "bounded maximum in-degrees", "multipartite tournaments" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }