Quadrangularity in Tournaments
Abstract
The pattern of a matrix M is a (0,1)matrix which replaces all nonzero entries of M with a 1. There are several contexts in which studying the patterns of orthogonal matrices can be useful. One necessary condition for a matrix to be orthogonal is a property known as combinatorial orthogonality. If the adjacency matrix of a directed graph forms a pattern of a combinatorially orthogonal matrix, we say the digraph is quadrangular. We look at the quadrangular property in tournaments and regular tournaments.
 Publication:

arXiv Mathematics eprints
 Pub Date:
 April 2004
 arXiv:
 arXiv:math/0404320
 Bibcode:
 2004math......4320L
 Keywords:

 Combinatorics;
 05C20;
 05C50
 EPrint:
 13 pages