报告题目:102 years of cosmological constant in Einstein's equations. Is Lambda really constant in light of observations?
报告人：Joan Solà Peracaula教授
报告时间：上午10:00-11:00
报告地点：二楼教师活动中心
Joan Solà Peracaula教授学术报告
报告题目 Title：102 years of cosmological constant in Einstein's equations. Is Lambda really constant in light of
observations?
报告时间 (Time)： 2019年10月15日上午10:00-11:00 (周二)
报告地点 (Room)： 二楼教师活动中心
报告摘要 (Abstract): In this talk, I will first review some historical aspects of the cosmological constant in
Einstein's equations, Lambda, as well as of the Cosmological Constant Problem associated to it.
The Lambda term is one of the fundamental ingredients of the standard model of cosmology, LambdaCDM.
Such term is usually associated to the energy density of the cosmic vacuum, and is assumed to be strictly
constant since its introduction by Einstein in 1917. I will assess if this assumption is still tenable in the light
of the modern cosmological data, in particular the possibility that the cosmic vacuum is slightly
dynamical, i.e. time-dependent. In particular, I will compare the traditional LambdaCDM model with the so-called
Running Vacuum Model (RVM), as well as with some quintessence scalar field models and parameterizations
of dynamical dark energy. My conclusion will suggest that vacuum dynamics may provide a better description
of the overall cosmological observations. I will also argue that we have grounded theoretical reasons in quantum
field theory and string theory to support a dynamical vacuum in an expanding universe.
报告人简介 (Bio)：
Prof. Dr. Joan Solà Peracaula
Since 2001, full Professor of Theoretical Physics and Cosmology, Universitat de Barcelona (UB)
Department of Quantum Physics and Astronomy. Formerly Associate Professor at the Universitat Autònoma de
Barcelona (UAB) and of the Institute of High Energy Physics (IFAE). Former Head of Department and of the
Theoretical High Energy Physics Group at UB. Senior researcher at the Institute of Cosmos Sciences (ICCUB)
(
http://icc.ub.edu/)
欢迎感兴趣的老师和同学参加。