The Physics & Astronomy Colloquium Series presents Sujeong Lee of Jet Propulsion Laboratory California Institute of Technology, discussing "Testing Cosmology with Dark Energy Survey" on Feburary 26.

Abstract: The clustering patterns of galaxies and the subtle distortions in their shapes due to weak gravitational lensing are powerful tools to study the large-scale distribution of matter in the Universe, and through that to learn about the nature of dark energy or modifications to General Relativity. Dark Energy Survey (DES) is the largest imaging survey to date, observing one-eighth of the sky between 2013 and 2019 and measuring the shapes and positions of more than 200 million galaxies. The final cosmology analysis of the complete six-year dataset will be released in the coming months. 

In this talk, I will present how DES uses these two key observables to test extensions to the standard ΛCDM cosmological model. I will describe our methods for constraining extended models, and present preliminary results from the complete six-year dataset.