Disproof of a Conjecture by Woodall on the Choosability of $K_{s,t}$-Minor-Free Graphs
Disproof of a Conjecture by Woodall on the Choosability of $K_{s,t}$-Minor-Free Graphs
In 2001, in a survey article about list coloring, Woodall conjectured that for every pair of integers $s,t \ge 1$, all graphs without a $K_{s,t}$-minor are $(s+t-1)$-choosable.
 In this note we refute this conjecture in a strong form: We prove that for every choice of constants $\varepsilon>0$ and $C \ge …