41 citations · 186 across the 29 of their papers we have counts for
16 papers · 1 filter
A Characterization of Circle Graphs in Terms of Total Unimodularity
Robert Brijder, Lorenzo Traldi
A graph has an associated multimatroid , which is equivalent to the isotropic system of studied by Bouchet. In previous work it was shown that is a ci…
Characterizing -matrices with only even-rank principal submatrices in terms of skew-symmetry
Robert Brijder
We show that every principal submatrix of a square matrix with only entries in has even rank if and only if is skew-symmetric up to multiplication of rows/colu…
Counterexamples to a conjecture of Las Vergnas
Robert Brijder, Hendrik Jan Hoogeboom
We present counterexamples to a 30-year-old conjecture of Las Vergnas [J. Combin. Theory Ser. B, 1988] regarding the Tutte polynomial of binary matroids.
A Characterization of Circle Graphs in Terms of Multimatroid Representations
Robert Brijder, Lorenzo Traldi
The isotropic matroid of a looped simple graph is a binary matroid equivalent to the isotropic system of . In general, is not regular, so it cannot b…
Orienting Transversals and Transition Polynomials of Multimatroids
Robert Brijder
Multimatroids generalize matroids, delta-matroids, and isotropic systems, and transition polynomials of multimatroids subsume various polynomials for these latter combinatorial str…
Isotropic matroids III: Connectivity
Lorenzo Traldi, Robert Brijder
The isotropic matroid of a graph is a binary matroid, which is equivalent to the isotropic system introduced by Bouchet. In this paper we discuss four notions of co…