Orbital matrices and graph theory-a project for the next century
by
Harald Gropp
Universität Heidelberg

Orbital matrices are generalizations of indicence matrices of symmetric 2-designs where the entries are nonnegative integers, not only 0 and 1. The conditions are corresponding like constant row sum and constant inner product. Already for entries 0, 1, 2 there is an enormous number of cases which have to be discussed. By describing the relations of the rows of the matrix by means of a graph the use of graph theory in order to solve existence problems of orbital matrices is possible.

Date received: October 31, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cafo-07.