Dual bipartite Q-polynomial distance-regular graphs

Abstract

We classify the dual bipartite Q-polynomial distance-regular graphs of diameter d ≥ 5 which are not bipartite. Results of Curtin and Nomura give a classification of the dual bipartite Q-polynomial distance-regular graphs of diameter d ≥ 6 which are bipartite. This completes a classification of the dual bipartite Q-polynomial distance-regular graphs of diameter d ≥ 6. © 1996 Academic Press Limited.