Our research spans a wide range of topics in cosmology, astrophysics, and particle/nuclear astrophysics. These include dark energy, dark matter, and galaxy formation; the high-energy astrophysics of cosmic rays, gamma rays, and neutrinos; and transient/multi-messenger astronomy. Our efforts in theory are closely coupled to those in experiment and observation, which include galaxy surveys, cosmic-ray and neutrino telescopes, and supernova surveys. This group is one of two in the Department that lead research centers (details below).This group is funded by the DOE, NASA, NSF, Moore Foundation, and Simons Foundation.