The Erdos-Posa Property for Directed Graphs

Saeed Akhoondian Amiri, Ken-Ichi Kawarabayashi, Stephan Kreutzer +1

A classical result by Erdos and Posa states that there is a function $f:\mathbb{N}\to \mathbb{N}$ such that for every $k$, every graph $G$ contains $k$ pairwise vertex…