Title
List colourings of multipartite hypergraphs
Abstract
Let chi(l)(G) denote the list chromatic number of the r-uniform hypergraph G. Extending a result of Alon for graphs, Saxton and the second author used the method of containers to prove that, if G is simple and d-regular, then chi l(G)>=(1/(r-1)+o(1))logrd. To see how close this inequality is to best possible, we examine chi(l)(G) when G is a random r-partite hypergraph with n vertices in each class. The value when r = 2 was determined by Alon and Krivelevich; here we show that chi l(G)=(g(r,alpha)+o(1))logrd almost surely, where d is the expected average degree of G and alpha=lognd. The function g(r,alpha) is defined in terms of "preference orders" and can be determined fairly explicitly. This is enough to show that the container method gives an optimal lower bound on chi(l)(G) for r = 2 and r = 3, but, perhaps surprisingly, apparently not for r >= 4.
Year
DOI
Venue
2019
10.1002/rsa.20848
RANDOM STRUCTURES & ALGORITHMS
Keywords
Field
DocType
hypergraph,list colouring
Discrete mathematics,Graph,Combinatorics,Multipartite,Vertex (geometry),Upper and lower bounds,Constraint graph,Hypergraph,Almost surely,Mathematics
Journal
Volume
Issue
ISSN
55.0
4.0
1042-9832
Citations 
PageRank 
References 
0
0.34
0
Authors
2
Name
Order
Citations
PageRank
Arès Méroueh111.03
Andrew Thomason27116.01