Joint IAS/PU Number Theory

Parahoric Subgroups and Supercuspidal Representations of p-Adic groups

Dick Gross
Harvard University
December 9, 2010

This is a report on some joint work with Mark Reeder and Jiu-Kang Yu. I will review the theory of parahoric subgroups and consider the induced representation of a one-dimensional character of the pro-unipotent radical. A surprising fact is that this induced representation can (in certain situations) have finite length. I will describe the parahorics and characters for which this occurs, and what the Langlands parameters of the corresponding irreducible summands must be.