Event Description
Paul Martini, PhD, Ohio State University
Astronomical observations have lead to advances in fundamental physics that include the development and verification of general relativity, the existence of dark matter, and the discovery of neutrino oscillations. I will describe how large astronomical surveys continue to provide a unique probe of many areas of physics, with a special focus on two surveys aimed at understanding the origin of cosmic acceleration, a phenomenon that could be explained by a breakdown of general relativity on the largest scales or some form of dark energy. I will present a summary of the latest cosmological results from the Dark Energy Survey, which has recently completed its fifth year of observations of 5000 square degrees of the southern sky. I will then describe the Dark Energy Spectroscopic Instrument (DESI), which is scheduled to begin a new sky survey in 2019. DESI will measure spectroscopic redshifts for over 35 million galaxies and quasars from the present to beyond redshift three across 14000 square degrees in the northern hemisphere. The DESI collaboration will use these data to measure the rate of cosmic expansion and the growth of structure, as well as test modified gravity models, inflation, and measure the sum of neutrino masses. I will describe the instrumentation, present an overview of the survey design, and summarize the forecasts for cosmological and other physical constraints. |
