Speaker: Roohi Dalal (Princeton)
New Cosmology Constraints from the Hyper Suprime-Cam Year 3 Data Release
The Hyper Suprime-Cam (HSC) survey is the deepest Stage III weak lensing experiment, going to ~26 mag with exquisite seeing. The depth and image quality achieved by HSC allow us to probe cosmology using weak lensing upto high redshifts, and these analyses serve as important preparatory studies for the next generation of weak lensing surveys. I will discuss our constraints on cosmological parameters using weak lensing cosmic shear power spectra measured from the Year 3 shear catalog of HSC, covering 416 square degrees of the northern sky. I will describe our cosmological analysis, including the steps we take to prevent confirmation bias as well as our modeling of various sources of systematic uncertainties. I will then discuss our new constraint on the S8 parameter, which describes the clumpiness of the matter distribution in the universe, and how it informs our understanding of the apparent 2-3 sigma tension between constraints on S8 from weak lensing experiments and those from the CMB. Finally, I will discuss ongoing and future work that can further shed light on the S8 tension, including an improved modeling of baryonic feedback at small scales.
For Zoom information, please contact the seminar coordinators.
