Dr Raghavan has made significant contribution on number theory. His work on modular forms of several variables has been considered basic and extends in a non-trivial way the ideas of Hecke and Siegel. He has proved important results in analytic continuation of Eisenstein-Siegel series. His characterization of singular Siegel modular forms answers a long standing question of Maass. His work on Diophantine approximation is a significant improvement on the earlier work of Davenport and Heilbronn.