Asymptotic Schur orthogonality relations for Heisenberg groups over local fields

Asymptotic Schur orthogonality relations are for irreducible unitary representations of locally compact groups that need not be discrete series, where $L^2$ pairing of matrix coefficients with respect to Haar measure is replaced by a limit of that with respect to a sequence of bounded measures. We show that such relations hold for Heisenberg groups over local fields. This is achieved in the framework of c-temperedness introduced by Kazhdan and Yom Din. The related condition of convergence to braiding operator is also shown.