On the observational side of cosmology, Tyson heads the Deep Lens Survey and the future Large Synoptic Survey Telescope (LSST). Becker, Boeshaar, Bradac, Fassnacht, Lubin and Wittman probe dark matter and dark energy through gravitational lensing, the reionization of the Universe with high-redshift quasars, and the assembly and evolution of large-scale structures with wide-area multi-wavelength surveys. They also conduct wide-field radio surveys and study low-mass stars and brown dwarfs. Theoretical faculty (Albrecht, Knox, and Kaloper) study the implications of modern ideas of high energy physics for the early Universe (and vice-versa), dark energy and dark matter, predict observable effects, and analyze and interpret cosmological data with an emphasis on its implications for fundamental physics.