On bipartite distance-regular graphs with exactly two irreducible T-modules with endpoint 2

Mark S. MacLean, Stefko Miklavic

Let $\Gamma$ denote a bipartite distance-regular graph with diameter $D\ge 4$ and valency $k\ge 3$. Let $X$ denote the vertex set of $\Gamma$, and let $A$ denote the adjacency matrix of $Γ…