Motivated by known examples of global integrals which represent automorphic
L-functions, this paper initiates the study of a certain two-dimensional array
of global integrals attached to any reductive algebraic group, indexed by
maximal parabolic subgroups in one direction and by unipotent conjugacy classes
in the other. Fourier coefficients attached to unipotent classes,
Gelfand-Kirillov dimension of automorphic representations, and an identity
which, empirically, appears to constrain the unfolding process are presented in
detail with examples selected from the exceptional groups.
This paper treats the problem of determining conditions for the Fourier
coefficients of a Maass-Hecke newform at cusps other than infinity to be
multiplicative. To be precise, the Fourier coefficients are defined using a
choice of matrix in SL(2, Z) which maps infinity to the cusp in question. Let c
and d be the entries in the bottom row of this matrix, and let N be the level.
In earlier work with Dorian Goldfeld and Min Lee, we proved that the
coefficients will be multiplicative whenever N divides 2cd. This paper proves
that they will not be multiplicative unless N divides 576cd.