The Dark Energy Survey

The Dark Energy Survey (DES) is a proposed 5‐year, 5000 deg 2 optical imaging survey, to 24th magnitude in the SDSS griz bands, that will use a new wide‐field 3 deg2 mosaic CCD camera on the Blanco 4m telescope at the Cerror Tololo Inter‐American Observatory (CTIO). The primary scientific goal of the DES is to probe the nature of dark energy using four complementary methods: galaxy clusters, weak gravitational lensing, galaxy angular correlations, and Type Ia supernovae. For each of these methods, the DES should determine the dark energy equation of state parameter w with a statistical precision of about 5–15%, assuming constant w but without strong priors on other cosmological parameters. By deriving dark energy constraints using four complementary sets of measurements made from the same data set and within a common analysis framework, we will obtain important crosschecks of our systematic errors and thereby make a substantial and robust advance in the precision of dark energy measurements.