Implications of vanishing Krein parameters on Delsarte designs, with applications in finite geometry

John Bamberg, Jesse Lansdown

In this paper we show that if $\theta$ is a $T$-design of an association scheme $(\Omega ,\mathcal{R})$, and the Krein parameters $q_{i,j}^h$ vanish for some $h\notin T$ and all $i, j \no…