A New Construction for the Tame Local Langlands Correspondence for GL(n,F), n a prime

Abstract

In this paper, we give a new construction of the tame local Langlands correspondence for GL(n,F), n a prime, where F is a p-adic field. In the tame case, supercuspidal representations of GL(n,F) are parameterized by characters of elliptic tori, but the local Langlands correspondence is unnatural because it involves a twist by some character of the torus. Taking the cue from real groups, supercuspidal representations should instead be parameterized by characters of covers of tori. Over the reals, Harish-Chandra described the characters of discrete series restricted to compact tori. They are naturally written in terms of functions on a double cover of real tori. We write down a natural analogue of Harish-Chandra's character for GL(n,F), and show that it is the character of a unique supercuspidal representation, away from the local character expansion. This paves the way for a natural construction of the local Langlands correspondence for GL(n,F).