Title of article :
About the second neighborhood problem in tournaments missing disjoint stars
Author/Authors :
ghazal, salman lebanese university - faculty of sciences i - department of mathematics, Lebanon , ghazal, salman universite claude bernard lyon - institute camille jordan - departement de mathematiques, France
Abstract :
Let D be a digraph without digons. Seymour’s second neighborhood conjecture states that D has a vertex v such that d+(v) ≤ 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.
Keywords :
oriented graph , out , neighborhood , second out , neighborhood , star
Journal title :
Electronic Journal of Graph Theory and Applications (EJGTA)
Journal title :
Electronic Journal of Graph Theory and Applications (EJGTA)
