Research is centered on the study of sources of gravitational radiation as well as other relativistic phenomena in astrophysics. A large part is devoted to the computation of oscillation frequencies of relativistic stars and black holes. The results are expected to be used in the extraction of physical characteristics of gravitational wave sources, after successful detection by the new generation of gravitational wave detectors that are now operating in several countries. In the study of sources of gravitational waves, we also use three-dimensional nonlinear simulations that are carried out on large super-computers. A recent result of this approach is the discovery of a new way to form supermassive black holes.