Title
Bisections of graphs
Abstract
A bisection of a graph is a bipartition of its vertex set in which the number of vertices in the two parts differ by at most 1, and its size is the number of edges which go across the two parts. In this paper, motivated by several questions and conjectures of Bollobas and Scott, we study maximum bisections of graphs. First, we extend the classical Edwards bound on maximum cuts to bisections. A simple corollary of our result implies that every graph on n vertices and m edges with no isolated vertices, and maximum degree at most n/3+1, admits a bisection of size at least m/2+n/6. Then using the tools that we developed to extend Edwards@?s bound, we prove a judicious bisection result which states that graphs with large minimum degree have a bisection in which both parts span relatively few edges. A special case of this general theorem answers a conjecture of Bollobas and Scott, and shows that every graph on n vertices and m edges of minimum degree at least 2 admits a bisection in which the number of edges in each part is at most (1/3+o(1))m. We also present several other results on bisections of graphs.
Year
DOI
Venue
2011
10.1016/j.jctb.2013.06.002
J. Comb. Theory, Ser. B
Keywords
DocType
Volume
maximum degree,large minimum degree,judicious bisection result,n vertex,maximum bisections,maximum cut,general theorem,classical edwards,m edge,minimum degree,discrete mathematics
Journal
103
Issue
ISSN
Citations 
5
0095-8956
7
PageRank 
References 
Authors
0.60
20
3
Name
Order
Citations
PageRank
Choongbum Lee19712.62
Po-Shen Loh213318.68
Benny Sudakov31391159.71