Tight Frames for Eigenspaces of the Laplacian on Dual Polar Graphs

We consider $\Gamma=(X,E)$ a dual polar graph and we give a tight frame on each eigenspace of the Laplacian operator associated to $\Gamma$. We compute the constants associated to each tight frame and as an application we give a formula for the product in the Norton algebra attached to the eigenspace corresponding to the second largest eigenvalue of the Laplacian.