Eisenstein Cohomology and ratios of critical values of Rankin-Selberg L-functions

Abstract

This is an announcement of results on rank-one Eisenstein cohomology of GL(N), with N > 1 an odd integer, and algebraicity theorems for ratios of successive critical values of certain Rankin-Selberg L-functions for GL(n) x GL(n') when n is even and n' is odd.Comment: Final version to appear in Comptes Rendus Math. Acad. Sci. Pari