On distance-regular graphs with smallest eigenvalue at least -m

Abstract

A non-complete geometric distance-regular graph is the point graph of a partial linear space in which the set of lines is a set of Delsarte cliques. In this paper, we prove that for a fixed integer m >= 2, there are only finitely many non-geometric distance-regular graphs with smallest eigenvalue at least -m, diameter at least three and intersection number c(2) >= 2. (C) 2010 Elsevier Inc. All rights reserved.