This book studies the modules arising in Fourier expansions of automorphic forms, namely Fourier term modules on SU(2,1), the smallest rank one Lie group with a non-abelian unipotent subgroup. It considers the "abelian" Fourier term modules connected to characters of the maximal unipotent subgroups of SU(2,1), and also the "non-abelian" modules, described via theta functions. A complete description of the submodule structure of all Fourier term modules is given, with a discussion of the consequences for Fourier expansions of automorphic forms, automorphic forms with exponential growth included.

Roelof W. Bruggeman was born in Zwolle, the Netherlands. He obtained his PhD at Utrecht University in 1972, and was a postdoctoral fellow at Yale University (1972-73). He has worked at Utrecht University since 1980, now as a guest after his retirement in 2005. In 2022 he became a corresponding member of the Academia Nacional de Ciencias in Córdoba, Argentina. The main research themes in his work are the spectral theory of Maass forms, the study of families of automorphic forms as a function of complex parameters, and the relation between automorphic forms and cohomology.