The size and the age of the universe / G.A. Tammann -- Active galaxies at large redshifts / M.S. Longair -- Observational cosmology with the cosmic microwave background / G.F. Smoot -- Future prospects in measuring the CMB power spectrum / P.M. Lubin -- Inflationary cosmology / M.S. Turner -- The signature of the universe / B.J.T. Jones -- Theory of the large-scale structure / S.F. Shandarin -- The origin of mater in the universe / L.A. Kofman -- New guises for old dark-matter suspects / E.W. Kolb -- On the unification of gravitational and inertial forces / D. Lynden-Bell -- Internal structure of astrophysical black holes / W. Israel -- Black hole entropy : external fac̜ade and internal reality / V. Frolov -- Accretion disks around black holes / M.A. Abramowicz -- Black hole X-ray transients / J.C. Wheeler -- X-rays and gamma ray from active galactic nuclei / R. Svensson -- Gamma-ray bursts : a challenge to relativistic astrophysics / M. Rees -- Probing black holes and other exotic objects with gravitational waves / K.S. Thorne -- The past and future of relativistic astrophysics / I.D. Novikov