Eisenstein Cohomology for Gln and the Special Values of Rankin-Selberg L-Functions: (Ams-203)This book studies the interplay between the geometry and topology of locally symmetric spaces, and the arithmetic aspects of the special values of L functions. The authors study the cohomology of locally symmetric spaces for GL(N) where the cohomology groups are with coefficients in a local system attached to a finite dimensional algebraic representation of GL(N). The image of the global cohomology in the cohomology of the Borel Serre boundary is