Speaker: Keith Bechtol, Large Synoptic Survey Telescope
Abstract: Over the past few decades, a “standard” but puzzling cosmological model has emerged that has passed increasingly stringent observational tests, and yet raises many new questions. What is causing the accelerated expansion of the Universe? What are the particle constituents of dark matter? Can we measure the influence of massive neutrinos on the growth of cosmic structure? The Dark Energy Survey (DES) is one of several ongoing experiments producing ever larger and more detailed maps of the night sky to address these questions via statistical inference from measurements of hundreds of millions of individual stars and galaxies. I will highlight several recent results from DES, including cosmology constraints from gravitational weak lensing, galaxy clustering, and supernovae, newfound dwarf galaxies and stellar streams, and the first optical detection of a kilonova explosion associated with a gravitational wave signal. I will conclude with a discussion of the next major experiment in this field, the Large Synoptic Survey Telescope (LSST), now under construction in Chile, with first light expected in 2020.