Representations of the p-adic GSpin4 and GSpin6 and the adjoint L-function

Abstract

We prove a conjecture of B. Gross and D. Prasad about determination of generic L-packets in terms of the analytic properties of the adjoint L-function for p-adic general even spin groups of semi-simple ranks 2 and 3. We also explicitly write the adjoint L-function for each L-packet in terms of the local Langlands L-functions for the general linear groups.