Testing Dark Energy with Galaxy Clustering and Lensing in the Dark Energy Survey

  • Aug. 13, 2021, 4:00 pm US/Central
  • Jack-Elvin Poole, Ohio State University

Galaxy surveys are fundamental tools of cosmology allowing us to measure the geometry and growth of structure in the universe. Using weak gravitational lensing and galaxy clustering from these surveys, we can directly trace the dark matter distribution and infer from this the properties of Dark Energy and Dark Matter. Recent measurements of this kind from the Dark Energy Survey (DES) have taken a major step towards understanding these phenomena. I will present these results, both using the combination of lensing and clustering (the so-called “3x2pt” analysis) and from measurement of the Baryonic Acoustic Oscillation from galaxy clustering. We find our results to be consistent with predictions from the Cosmic Microwave Background within the Lambda-CDM model. When combining with external data we can provide a 3% measurement of the Dark Energy Equation of state, consistent with the Lambda-CDM value. Our BAO measurement is a 2.7% measurement of the angular diameter distance at a redshift of 0.835, competitive with the transverse measurements of spectroscopic surveys. As well as providing statistically powerful tests of Dark Energy and the LCDM model, DES will be a major testbed for the methodological developments required for the next generation of experiments Euclid, LSST, DESI, to be successful.