报告人：郭斌博士（巴黎萨克雷大学）

标题：Are there echoes of gravitational waves?

时间：2023年2月17日 周五16:00

地点：理工楼1226

邀请人：刘玉孝

报告摘要：

In several approaches to understanding black hole microstates, the semiclassical black hole is replaced by an Exotic Compact Object (ECO). It has been conjectured that gravitational waves emitted by the merger of ECOs can reflect off the ECOs and produce a detectable‘echo’. We argue that while a part of the wave can indeed reflect off the surface of an ECO, this reflected wave will get trapped by a new closed trapped surface produced by its own backreaction. Thus no detectable signal of the echo will emerge to infinity. The only assumption in this analysis is that causality is maintained to leading order in gently curved spacetime. Thus if echoes are actually detected, then we would face a profound change in our understanding of physics.

个人简介：

郭斌，2008 - 2015兰州大学本科、硕士，2015 - 2017英属哥伦比亚大学硕士，2017 - 2021俄亥俄州立大学博士，2021 -至今巴黎萨克雷大学博士后。主要从事黑洞微观态fuzzball理论的研究。