Title
Balanced decompositions of a signed graph
Abstract
The balanced decomposition number (b.d.n.) δ 0 ( Σ ) of a signed graph Σ is the smallest number of balanced subsets into which its edges can be partitioned. (A special case is decomposition of a graph into bipartite subgraphs.) The connected b.d.n. δ 1 ( Σ ) is the same, but the subsets must also be connected. The balanced partition number (b.p.n.) π 0 ( Σ ) is the smallest size of a partition of the vertices into subsets inducing balanced subgraphs; the connected b.p.n. π 1 ( Σ ) is similar but the induced subgraphs must be connected. We use signed graph coloring theory to prove that δ 0 = 1 + ⌈log 2 π 0 ⌉ and that δ 0 is analogous to a critical exponent in the sense of Crapo and Rota. We deduce bounds on δ 0 and values for special signed graphs. We show that δ 0 is computationally about as complex as the chromatic number. We prove that, for a complete signed graph, δ 1 = δ 0 ; more strongly, with three exceptions a minimal balanced decomposition exists into connected and spanning edge sets. And we show that, of δ 1 and 1 + ⌈log 2 π 1 ⌉, neither is always at least as large as the other.
Year
DOI
Venue
1987
10.1016/0095-8956(87)90026-8
J. Comb. Theory, Ser. B
Keywords
Field
DocType
balanced decomposition,signed graph
Discrete mathematics,Combinatorics,Modular decomposition,Line graph,Signed graph,Graph power,Distance-hereditary graph,Petersen graph,Strongly connected component,Mathematics,Complement graph
Journal
Volume
Issue
ISSN
43
1
Journal of Combinatorial Theory, Series B
Citations 
PageRank 
References 
6
0.43
4
Authors
1
Name
Order
Citations
PageRank
T. Zaslavsky129756.67