Bounds for multiplicities of automorphic forms of cohomological type on GL_2

Abstract

We prove various results on the cohomology of arithmetic lattices arising from quaternion algebras over a number field with at least one complex place, including a strong restriction on the allowable weights of cuspidal cohomological automorphic forms and a conditional power saving for their multiplicities when the associated locally symmetric space is a hyperbolic 3-manifold.

23 pages, submitted

References in corpus (2)

• Pro-p groups and towers of rational homology spheres
• The cohomology of lattices in SL(2,C)