Cosmology with the Large Synoptic Survey Telescope: an Overview

The Large Synoptic Survey Telescope (LSST) is a high etendue imaging facility that is being constructed atop Cerro Pachon in Northern Chile. It is scheduled to begin science operations in 2022. With an 8.4m (6.5m effective) aperture, a three-mirror design achieving a seeing-limited 9.6deg^2 field of view, and a 3.2 Gigapixel camera, the LSST has the deep-wide-fast imaging capability to carry out an 18,000deg^2 survey in six passbands (ugrizy) to a coadded depth of r~27.5 over 10 years using 90% of its observational time. The remaining 10% will be devoted to deeper and faster time-domain observations and smaller surveys. In total, each patch of the sky in the main survey will receive 800 visits allocated across the six passbands with 30s exposure visits. The huge volume of high-quality LSST data will provide a wide range of science opportunities and open a new era of precision cosmology with unprecedented statistical power and tight control of systematic errors. In this review, we give a brief account of the LSST cosmology program with an emphasis on dark energy investigations. The LSST will address dark energy physics and cosmology in general by exploiting diverse precision probes including large-scale structure, weak lensing, type Ia supernovae, galaxy clusters, and strong lensing. Combined with the cosmic microwave background data, these probes form interlocking tests on the cosmological model and the nature of dark energy. The LSST data products will be made available to the U.S. and Chilean scientific communities and to international partners with no proprietary period. Close collaborations with coeval surveys observing at a variety of wavelengths, resolutions, depths, and timescales will be a vital part of the LSST science program, which will not only enhance specific studies but also allow a more complete understanding of the universe through different windows.