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Do We Understand Cosmic Structure Growth? by Prof. Blake D. Sherwin

May 17, 2024 @ 3:30 pm - 4:30 pm

About the speaker: Prof. Blake D. Sherwin is a Professor of Cosmology and Astrophysics at the Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge. He obtained his PhD from Princeton University in 2013. After that, he was a postdoctoral fellow at UC Berkeley, Lawrence Berkeley Laboratory, and the University of Cambridge. Then, he became an assistant Professor at Cambridge in 2017. He has been awarded several honorable awards and fellowships, such as the Miller Research Fellowship, NASA Einstein Fellowship, and STFC Ernest Rutherford Fellowship. He is part of several international CMB experiments such as Atacama Cosmology Telescope (ACT), Simons Observatory (SO), LiteBIRD and CMB-S4.

Abstract: One of the most powerful tests of our cosmological model is to verify the predicted growth of large-scale structure with time. Intriguingly, many recent measurements have reported small discrepancies in such tests of structure growth (“the S8 tension”), which could hint at systematic errors or even new physics. Motivated by this puzzling situation, I will present new determinations of cosmic structure growth using CMB gravitational lensing measurements from the Atacama Cosmology Telescope (ACT). These ACT DR6 CMB lensing measurements allow us to directly map the dark matter distribution in projection out to high redshifts; new cross-correlations of CMB lensing with unWISE galaxies also allow us to probe the matter tomographically. I will discuss the implications of our lensing results for the validity of our standard cosmological model as well as for key cosmological parameters such as the neutrino mass and Hubble constant.

The recording of the talk is available on the CMB-Bharat YouTube channel.

Details

Date:
May 17, 2024
Time:
3:30 pm - 4:30 pm
Event Category:
Website:
https://forms.gle/rjnM4ZNJ8uP9eBkRA