Hadwiger's Conjecture for 3-Arc Graphs
Keywords:
Hadwiger's conjecture, Graph colouring, Graph minor, $3$-Arc graph
Abstract
The 3-arc graph of a digraph $D$ is defined to have vertices the arcs of $D$ such that two arcs $uv, xy$ are adjacent if and only if $uv$ and $xy$ are distinct arcs of $D$ with $v\ne x$, $y\ne u$ and $u,x$ adjacent. We prove Hadwiger's conjecture for 3-arc graphs.