应刘玉孝教授邀请，济南大学物理科学与技术学院郭俊起老师来访并作学术报告。欢迎广大师生届时参加！

题目：Critical phenomena in gravitational collapse

时间：2018年12月17日（周一）下午16:00

地点：齐云楼525报告厅

摘要：Critical phenomena in gravitational collapse have been an intriguing topic in gravitational physics, which are caused by the nonlinearities of Einstein equations and were originally discovered by Choptuik via numerical simulations in 1993. In this talk, some analytic information on critical collapse will be presented. Regarding the methodology, we combine numerical simulations and asymptotic analysis, and synthesize critical collapse, spacetime singularities, and complex science. By fitting the numerical results with a typical log-periodic formula in complex science, we obtain the first approximate analytic expression for the metric components near the center. The spacetime near the center is nearly conformally flat. The slopes for the metric components and the scalar field versus the logarithm of the proper time are at the same order of magnitude as those in black hole formation, respectively. In this sense, one rough analytic explanation to the values of these slopes is given for the first time.

个人简介：郭俊起，2001年获得烟台师范学院理学学士学位，2004年及2008年分别获得华中科技大学及美国密西西比大学理论物理硕士学位，2014年8月获得加拿大Simon Fraser University理论物理博士学位。2014年9月至2016年8月为印度Tata Institute of Fundamental Research博士后。2016年9月任济南大学物理科学与技术学院讲师。研究方向为引力塌缩、时空奇点、黑洞物理学与数值相对论。