The Second Neighborhood Conjecture For Oriented Graphs Missing Generalized Combs
Salman Ghazal · arXiv (Cornell University) · 2016
Seymour's Second Neighborhood Conjecture asserts that every oriented graph has a vertex whose ?rst out-neighborhood is at most as large as its second out-neighborhood. We introduce the generalized comb, characterize them and prove that every oriented graph missing it satisfies this conjecture.