Residual automorphic forms and spherical unitary representations of exceptional groups

Exceptional Unitary Representations of Semisimple Lie Groups

Let G be a noncompact simple Lie group with finite center, let K be a maximal compact subgroup, and suppose that rank G = rank K. If G/K is not Hermitian symmetric, then a theorem of Borel and de Siebenthal gives the existence of a system of positive roots relative to a compact Cartan subalgebra so that there is just one noncompact simple root and it occurs exactly twice in the largest root. Le...

Spherical unitary representations for split groups

1. Basic examples.

Explicit Calculations of Automorphic Forms for Definite Unitary Groups

I give an algorithm for computing the full space of automorphic forms for definite unitary groups over Q, and apply this to calculate the automorphic forms of level G(Ẑ) and various small weights for an example of a rank 3 unitary group. This leads to some examples of various types of endoscopic lifting from automorphic forms for U1 × U1 × U1 and U1 × U2, and to an example of a non-endoscopic f...

Automorphic representations with prescribed ramification for unitary groups

Let F be a totally real number field, n a prime integer, and G a unitary group of rank n defined over F that is compact at infinity. We prove an asymptotic formula for the number of automorphic representations of G whose factors at finitely many places are prescribed up to inertia. These factors are specified by local inertial types, and the proof relies crucially on a bound on the traces of th...

Discontinuous Groups and Automorphic Forms