The Astrophysics and Cosmology Group consists of about ten staff members and several postdocs and PhD students. Together with the Astroparticle Physics group we address fundamental questions in the very broad fields of astrophysics, cosmology and particle physics. Our research interests include: analysis and interpretation of cosmic microwave background and sub-mm surveys, large-scale structure surveys, cluster physics, galaxy formation and evolution, dark energy, dark matter, galactic and extragalactic black holes, stellar structure and evolution, high-energy astrophysics, relativistic astrophysics, early universe physics and gravitation theory. In the Astrophysics and Cosmology PhD curriculum our students are trained to become junior scientists with lecture courses followed by research work, participation to international collaborations, conferences and observational projects. Researchers, postdocs and students working at SISSA can also take advantage of the rich environment of scientific institutions present in the Trieste area, such as the International Centre for Theoretical Physics (ICTP), the Istituto Nazionale di Fisica Nucleare (INFN) and the Istituto Nazionale di Astrofisica (INAF-Astronomical Observatory of Trieste).