报告题目: Galaxy Clusters: A Standard Cannon for Cosmology

　　报告人: Prof.Christopher J Miller（Professor of Astronomy, Professor of Physics， University of Michigan, Ann Arbor USA）

　　报告摘要：Einstein’s theory of general relativity (GR) entwines the dynamics of matter-energy and the universe's spacetime expansion. Recent authors have revised our understanding of the mathematics of dynamical tracers within the context of GR for an accelerating space-time metric. As a consequence, we have a new understanding of how the escape speed relates to the local potential via the Poisson equation. General relativity requires that the escape velocity for a massive extended object like a galaxy cluster be reduced compared to its Newtonian counterpart. In fact, the combined weak lensing and escape profiles of clusters provide a new dynamical probe of the expansion history of the universe. I will give a description of the theory, results from tests using increasingly realistic simulations, and examples from the first applications of this technique to real data. I will then discuss the future prospects of this new cosmological tool in the context of surveys like LSST and DESI.

　　报告时间：2023年4月19日（星期三），下午2:00-3:00

　　报告地点：仙林园区3号楼302会议室

欢迎大家参加！