Dark Energy Survey Key Science:

The observed cosmic acceleration or dark energy is a fundamental challenge to our understanding of gravity and the expanding universe. Many current projects seek to study the dark energy through its effect on the expansion history and growth of structures. Today, interesting constraints on the dark energy equation of state parameter w are only available when multiple, independent datasets are combined. Each dataset by itself provides only weak constraints on w, making it difficult to meaningfully test consistency of the datasets before they are combined. We have designed an experiment that will address the nature of the dark energy using four independent techniques. In the Dark Energy Survey, each of these techniques will deliver constraints on constant w models that are stronger than the best available combined constraints today. Combining these independent constraints will deliver w constraints at the percent level and provide a firm foundation for progress in our understanding of gravity.

The design driver for the DES is a multiband optical galaxy cluster survey coordinated with the South Pole Telescope mm-wave survey. The dataset required to deliver redshifts for the Sunyaev-Zel'dovich Effect detected clusters is also well suited for a weak lensing study and a galaxy angular power spectrum study. In addition, the non-photometric time can be used to carry out an extensive supernova distance survey.

The four key dark energy science projects are:

• A galaxy cluster study in collaboration with the South Pole Telescope cluster survey
• A weak lensing study of the fluctuation spectrum of dark matter
• A galaxy angular power spectrum study
• A SNe Ia study that will deliver ~2000 SNe Ia over the life of the project

Each of these projects will be the best in class on the timescale of this survey. In addition, each will deliver constraints on constant w models of 0.05 to 0.10. Together, these four experiments will deliver percent level constraints on a constant dark energy equation of state parameter w. Very strong constraints on the time evolution of the equation of state parameter are also possible. This will be the definitive dark energy experiment of its time, and it will lay the foundations for the much longer timescale Supernova Acceleration Probe (SNAP) and Large Synoptic Survey Telescope (LSST).

Please follow the Documents link for further information.

This 5000 square degree deep g,r,i and z band survey will be a rich dataset for many other science projects. The reduced individual images will be made available to the community one year after they are acquired on the telescope. Co-added images and object catalogs will be released twice: once halfway through the five year survey, and then again one year after the completion of the survey.