About the second neighborhood problem in tournaments missing disjoint stars

<p>Let $D$ be a digraph without digons. Seymour's second neighborhood conjecture states that $D$ has a vertex $v$ such that $d^+(v) \leq d^{++}(v)$. Under some conditions, we prove this conjecture for digraphs missing $n$ disjoint stars. Weaker conditions are required when $n = 2$ or $3$....

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Bibliographic Details
Main Author: Salman Ghazal
Format: Article
Language:English
Published: Indonesian Combinatorial Society (InaCombS); Graph Theory and Applications (GTA) Research Centre; University of Newcastle, Australia; Institut Teknologi Bandung (ITB), Indonesia 2016-10-01
Series:Electronic Journal of Graph Theory and Applications
Subjects:
Online Access:https://www.ejgta.org/index.php/ejgta/article/view/189
Description
Summary:<p>Let $D$ be a digraph without digons. Seymour's second neighborhood conjecture states that $D$ has a vertex $v$ such that $d^+(v) \leq d^{++}(v)$. Under some conditions, we prove this conjecture for digraphs missing $n$ disjoint stars. Weaker conditions are required when $n = 2$ or $3$. In some cases we exhibit two such vertices.</p>
ISSN:2338-2287