Pseudodifferential analysis, introduced in this book in a way adapted to
the needs of number theorists, relates automorphic function theory in
the hyperbolic half-plane Π to automorphic distribution theory in the
plane. Spectral-theoretic questions are discussed in one or the other
environment: in the latter one, the problem of decomposing automorphic
functions in Π according to the spectral decomposition of the modular
Laplacian gives way to the simpler one of decomposing automorphic
distributions in R2 into homogeneous components. The Poincaré
summation process, which consists in building automorphic distributions
as series of g-transforms, for g E SL(2*;*Z), of some initial
function, say in S(R2), is analyzed in detail. On Π, a
large class of new automorphic functions or measures is built in the
same way: one of its features lies in an interpretation, as a spectral
density, of the restriction of the zeta function to any line within the
critical strip.
The book is addressed to a wide audience of advanced graduate students
and researchers working in analytic number theory or pseudo-differential
analysis.