Fall 2021 Physics Colloquium: Connecting cosmology and galaxy formation with weak lensing

Abstract: Will present the cosmological results from the Dark Energy Survey (DES) using its first three years of data taken using the Dark Energy Camera on the 4m Blanco telescope at CTIO. This analysis spans the full DES footprint, more than 4000 sq. deg. of sky, with the final shear catalogue containing more than 100 million galaxies, constituting the most powerful weak lensing dataset to date. The comparison of DES cosmological constraints on dark matter and dark energy from WL and LSS in the low-redshift Universe to CMB constraints provides an unprecedented test of the standard cosmological model, across high and low redshift. Next, I will show preliminary results that compare the clustering and lensing signals of luminous red galaxies from the Baryon Oscillation Spectroscopic Survey - previously called `Lensing is Low’. I’ll show how these measurements are not only interesting for cosmology on linear scales, but as probes of galaxy formation on small scales. (Zoom only - see link below).