On a Generalization of Motohashi's Formula: Non-archimedean Weight Functions

Abstract: This is a continuation of the adelic version of Kwan's formula. At non-archimedean places we give a bound of the weight function on the mixed moment side, when the weight function on the $\mathrm{PGL}_3 \times \mathrm{PGL}_2$ side is nearly the characteristic function of a short family. Our method works for any tempered representation $\Pi$ of $\mathrm{PGL}_3$, and reveals the structural reason for the appearance of Katz's hypergeometric sums in a previous joint work with P.Xi.