Dark Energy Survey Year 3 Results: Cosmology from Weak Lensing and Galaxy Clustering
Abstract
Wide and deep galaxy imaging surveys are key to measuring structure growth over cosmic time and expanding our understanding of dark matter and dark energy. In recent years, observations of large-scale structure in the 'late-time Universe' have measured a matter clustering amplitude that is curiously low compared to predictions from the cosmic microwave background ('early-time Universe'), with an estimated significance of 2-3 sigma. A few months ago, the Dark Energy Survey released cosmology constraints from galaxy clustering and weak gravitational lensing based on its first three years of observations. I will give an overview of the DES Y3 analysis, present the main results, and discuss how they fit into the bigger picture of early-time and late-time constraints. Along the way, I will comment on historical context, methodological advances, and the path ahead with the next generation of wide and deep galaxy imaging surveys.
