# Neven Grbac

*University Rijeka*

Title: | Eisenstein Series in Arithmetic and Geometry |

Abstract: | The spectral decomposition of the space of square-integrable automorphic forms is an important problem in the arithmetic theory of automorphic forms on the adelic points of a (connected) reductive algebraic group defined over a number field. The geometric importance of the space of all automorphic forms is seen from their relation to the cohomology of arithmetic (congruence) subgroups. In approaching both problems the Eisenstein series play one of the key roles. We would like to explain here some recent results in both directions. Although essentially of different nature, the common ground for these results is the study of analytic properties of Eisenstein series. |