Seymour's second neighbourhood conjecture for quasi-transitive oriented graphs
نویسندگان
چکیده
Seymour’s second neighbourhood conjecture asserts that every oriented graph has a vertex whose second out-neighbourhood is at least as large as its out-neighbourhood. In this paper, we prove that the conjecture holds for quasi-transitive oriented graphs, which is a superclass of tournaments and transitive acyclic digraphs. A digraph D is called quasitransitive is for every pair xy, yz of arcs between distinct vertices x, y, z, xz or zx (“or” is inclusive here) is in D.
منابع مشابه
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عنوان ژورنال:
- CoRR
دوره abs/1704.01389 شماره
صفحات -
تاریخ انتشار 2017