{ "id": "math/0404320", "version": "v1", "published": "2004-04-18T19:45:27.000Z", "updated": "2004-04-18T19:45:27.000Z", "title": "Quadrangularity in Tournaments", "authors": [ "J. Richard Lundgren", "Simone Severini", "Dustin J. Stewart" ], "comment": "13 pages", "categories": [ "math.CO", "quant-ph" ], "abstract": "The pattern of a matrix M is a (0,1)-matrix which replaces all non-zero 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.", "revisions": [ { "version": "v1", "updated": "2004-04-18T19:45:27.000Z" } ], "analyses": { "subjects": [ "05C20", "05C50" ], "keywords": [ "quadrangularity", "non-zero entries", "combinatorially orthogonal matrix", "quadrangular property", "orthogonal matrices" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......4320L" } } }