Decomposition Spectrale et Series d'Eisenstein

The decomposition of the space L2 (G(Q)\G(/A)), where G is a reductive group defined over (Q and /A is the ring of adeles of (Q, is a deep problem at the intersection of number and group theory. Langlands reduced this decomposition to that of the (smaller) spaces of cuspidal automorphic forms for certain subgroups of G. The present book describes this proof in detail. The starting point is the theory of automorphic forms, which can also serve as a first step towards understanding the Arthur...