Title
Biased graphs. VII. Contrabalance and antivoltages
Abstract
We develop linear representation theory for bicircular matroids, a chief example being a matroid associated with forests of a graph, and bicircular lift matroids, a chief example being a matroid associated with spanning forests. (These are bias and lift matroids of contrabalanced biased graphs.) The theory is expressed largely in terms of antivoltages (edge labellings that defy Kirchhoff's voltage law) with values in the multiplicative or additive group of the scalar field. We emphasize antivoltages with values in cyclic groups and finite vector spaces since they are crucial for representing the matroids over finite fields; and integer-valued antivoltages with bounded breadth since they are crucial in constructions. We find bounds for the existence of antivoltages and we solve some examples. Other results: The number of antivoltages in an abelian group is a polynomial function of the group order, and the number of integral antivoltages with bounded breadth is a polynomial in the breadth bound. We conclude with an application to complex representation. There are many open questions.
Year
DOI
Venue
2007
10.1016/j.jctb.2007.03.001
J. Comb. Theory, Ser. B
Keywords
Field
DocType
abelian group,bias matroid,cyclic group,matroid representation,additive group,bicircular lift matroids,antivoltage,bicircular matroid,frame matroid,integer-valued antivoltages,integral antivoltages,biased graph,transversal matroid,spanning forest matroid,bicircular lift matroid,bounded breadth,gain graph,bicircular matroids,forest matroid,group order,contrabalance,chief example,representation theory,scalar field,vector space,finite field
Matroid,Discrete mathematics,Bicircular matroid,Combinatorics,Gain graph,Matroid representation,Matroid partitioning,Biased graph,Graphic matroid,Mathematics,Bounded function
Journal
Volume
Issue
ISSN
97
6
Journal of Combinatorial Theory, Series B
Citations 
PageRank 
References 
0
0.34
7
Authors
1
Name
Order
Citations
PageRank
T. Zaslavsky129756.67