15 search results - page 3 / 3 » On the chromatic number of an oriented matroid |
COMBINATORICS
2006
13 years 8 months ago
2006
A homomorphism from an oriented graph G to an oriented graph H is a mapping from the set of vertices of G to the set of vertices of H such that -----(u)(v) is an arc in H whenever...
EJC
2006
13 years 8 months ago
2006
We study the positive Bergman complex B+ (M) of an oriented matroid M, which is a certain subcomplex of the Bergman complex B(M) of the underlying unoriented matroid M. The positiv...
JCO
2007
13 years 8 months ago
2007
We consider the problem of orienting the edges of a graph so that the length of a longest path in the resulting digraph is minimum. As shown by Gallai, Roy and Vitaver, this edge ...
CCCG
2001
13 years 9 months ago
2001
A recent progress on the complete enumeration of oriented matroids enables us to generate all combinatorial types of small point configurations and hyperplane arrangements in gene...
DAM
2011
13 years 3 months ago
2011
An arc of a graph is an oriented edge and a 3-arc is a 4-tuple (v, u, x, y) of vertices such that both (v, u, x) and (u, x, y) are paths of length two. The 3-arc graph of a graph ...