2020/10/12 by Postle, Luke · 2 citations
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2010.05999
In 1943, Hadwiger conjectured that every graph with no Kt minor is (t-1)-colorable for every t≥ 1. In the 1980s, Kostochka and Thomason independently proved that every graph with no Kt minor has average degree O(t√(log t)) and hence is O(t√(log t))-colorable. Recently, Norin, Song and the author showed that every graph with no Kt minor is O(t(log t)β)-colorable for every β> 1/4, making the first improvement on the order of magnitude of the O(t√(log t)) bound. Building on that work, we previously showed that every graph with no Kt minor is O(t (log t)β)-colorable for every β> 0. More specifically, they are O(t ⋅ (log log t)6)-colorable. In this paper, we extend that work to the list and odd generalizations of Hadwiger's conjecture.