Title
Islands in Graphs on Surfaces.
Abstract
An island in a graph is a set X of vertices such that each element of X has few neighbors outside X. In this paper, we prove several bounds on the size of islands in large graphs embeddable on fixed surfaces. As direct consequences of our results, we obtain the following: (1) Every graph of genus g can be colored from lists of size 5, in such a way that each monochromatic component has size O(g). Moreover, all but O(g) vertices lie in monochromatic components of size at most 3. (2) Every triangle-free graph of genus g can be colored from lists of size 3, in such a way that each monochromatic component has size O(g). Moreover, all but O(g) vertices lie in monochromatic components of size at most 10. (3) Every graph of girth at least 6 and genus g can be colored from lists of size 2, in such a way that each monochromatic component has size O(g). Moreover, all but O(g) vertices lie in monochromatic components of size at most 16. While (2) is optimal up to the size of the components, we conjecture that the size of the lists can be decreased to 4 in (1), and the girth can be decreased to 5 in (3). We also study the complexity of minimizing the size of monochromatic components in 2-colorings of planar graphs.
Year
DOI
Venue
2016
10.1137/140957883
SIAM JOURNAL ON DISCRETE MATHEMATICS
Keywords
Field
DocType
coloring,graphs on surfaces,monochromatic components
Discrete mathematics,Graph,Combinatorics,Monochromatic color,Colored,Vertex (geometry),Mathematics
Journal
Volume
Issue
ISSN
30
1
0895-4801
Citations 
PageRank 
References 
2
0.37
10
Authors
2
Name
Order
Citations
PageRank
louis esperet114824.86
Pascal Ochem225836.91