Triangle packings and 1-factors in oriented graphs

dc.creatorKeevash, Peter
dc.creatorSudakov, Benny
dc.date2008-06-12
dc.date.accessioned2026-07-07T09:44:09Z
dc.date.available2026-07-07T09:44:09Z
dc.descriptionAn oriented graph is a directed graph which can be obtained from a simple undirected graph by orienting its edges. In this paper we show that any oriented graph G on n vertices with minimum indegree and outdegree at least (1/2-o(1))n contains a packing of cyclic triangles covering all but at most 3 vertices. This almost answers a question of Cuckler and Yuster and is best possible, since for n = 3 mod 18 there is a tournament with no perfect triangle packing and with all indegrees and outdegrees (n-1)/2 or (n-1)/2 \pm 1. Under the same hypotheses, we also show that one can embed any prescribed almost 1-factor, i.e. for any sequence n_1,...,n_t with n_1+...+n_t < n-O(1) we can find a vertex-disjoint collection of directed cycles with lengths n_1,...,n_t. In addition, under quite general conditions on the n_i we can remove the O(1) additive error and find a prescribed 1-factor.
dc.description22 pages, 1 figure
dc.identifierhttps://arxiv.org/abs/0806.2027
dc.identifierhttp://arxiv.org/abs/0806.2027
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/162772
dc.subjectCombinatorics
dc.subject05C20, 05C70
dc.titleTriangle packings and 1-factors in oriented graphs
dc.typetext

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