HEP-Astro Seminar | Cosmological Constraints from Weak Gravitational Lensing Analysis of KiDS, DES, and WFIRST

In the widely accepted standard model of cosmology, the Universe is dominated by a dark sector, composed of dark matter and dark energy. A powerful technique for studying this dark sector exploits gravitational lensing, the phenomenon whereby the path of light travelling from distant galaxies (and as far away as the cosmic microwave background) is deflected by intervening mass structures along the line of sight. The lensing effect is sensitive to all matter, whether visible or dark, and can inform our understanding of the nature and evolution of the Universe. However, the amplitude of the effect is tiny and can only be detected by averaging over many galaxies. Ongoing photometric galaxy surveys such as the Kilo Degree Survey (KiDS) and the Dark Energy Survey (DES) are providing the statistical power necessary to place precise constraints on the cosmological model. Much effort is also dedicated toward understanding potential sources of systematic error to ensure that the accuracy of these constraints is commensurate to their precision. I will describe the most recent cosmological lensing results from KiDS and DES and discuss some of the main challenges we face ahead of surveys that will be undertaken with future experiments such as the Wide Field Infrared Survey Telescope (WFIRST).