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Speaker: Roohi Dalal (Princeton) – Title: New Cosmology Constraints from the Hyper Suprime-Cam Year 3 Data Release
November 21 @ 4:00 pm - 5:00 pm
Research Progress Meeting
Date: November 21, 2023
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Roohi Dalal (Princeton)
Title: New Cosmology Constraints from the Hyper Suprime-Cam Year 3 Data Release
Abstract: The Hyper Suprime-Cam (HSC) survey is the deepest present-day weak lensing experiment, going to ~26 mag with exquisite image quality. This combination of depth and image quality achieved by HSC allows us to probe cosmology using weak gravitational lensing up to high redshifts, and these analyses serve as important preparatory studies for the next generation of weak lensing surveys, particularly the Vera C. Rubin Observatory. 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 systematic effects. The quantity best constrained by our analysis is the parameter S8, which describes the clumpiness of the matter distribution in the universe. From our analysis, and other weak lensing analyses with different surveys, there is a 2-3 sigma detection of a tension in the S8 measurements from weak lensing and those from the cosmic microwave background. While this could suggest that our cosmological model is incomplete, I will discuss ongoing and future work that can further shed light on this tension, including an improved modeling of baryonic feedback at small scales.
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Meeting ID: 956 7989 2182