【5.17; Seminar】2024年粒子天体物理重点实验室系列学术报告 #21：Searching for Cosmological Concordance with New Physics in the Dark Sector: Hints and Challenges

时间/Time: 5月17日上午9:00/Friday，May 17th at 9:00 AM (Beijing time)

地点/Location: 天体楼三楼会议室/Particle Astrophysics Building 3rd floor meeting room

报告人/Speaker: Colin Hill（Columbia University）

题目/Title: Searching for Cosmological Concordance with New Physics in the Dark Sector: Hints and Challenges

主持人/Host: 李雅琼/Yaqiong LI

ZOOM Meeting ID: 91804325137

Password：418991

摘要/Abstract: I will discuss recent and ongoing work focused on attempts to restore concordance amongst cosmological data sets, motivated by discrepancies between some measurements of the cosmic expansion rate (H_0) and the matter clustering amplitude (S_8).  Particular attention will be paid to scenarios invoking new physics in the high-redshift universe, including models featuring interactions between the dark matter and an early dark energy (EDE) scalar field, as well as models featuring scattering between dark matter and the late-time dark energy field.  I will discuss constraints on these models derived using CMB measurements from the Planck satellite and the Atacama Cosmology Telescope (ACT), amongst other data sets.  I will also present new constraints on canonical axion-like EDE models derived from the Lyman-alpha forest, which pose a major challenge for this scenario to resolve the Hubble tension.  Finally, I will conclude with a look ahead to the unprecedented constraining power of upcoming CMB analyses with ACT Data Release 6.

个人简介/Biography:

Colin Hill joined the Columbia University Physics Department as an assistant professor in August 2019. He received a Ph.D. in astrophysical sciences from Princeton University in 2014, following undergraduate and master's degrees at MIT and Cambridge University, respectively. He was a Junior Fellow in the Simons Society of Fellows, hosted at Columbia, from 2014-2017 and a postdoctoral member at the Institute for Advanced Study from 2017-19. He held a joint position as an Associate Research Scientist at the Center for Computational Astrophysics at the Flatiron Institute from 2019-2022. His work was recognized with a Sloan Research Fellowship in 2022 and is also supported by NASA, NSF, and the Department of Energy.