Bipartite distance-regular graphs with an eigenvalue of multiplicity \(k\)
We show that, if a bipartite distance-regular graph of valency \(k\) has an eigenvalue of multiplicity \(k\), then it becomes 2-homogeneous. Combined with a result on bipartite 2-homogeneous distance-regular graphs by K. Nomura, we have a classification of such graphs.
scientific article; zbMATH DE number 839133