报告时间：2021 年 3 月 26 日（周五）15：30                                       

                                                                 

报告地点：在线报告（ 腾讯会议 ID : 912 642 873）

报告摘要：Penrose et al. investigated the physical incoherence of the spacetime with negative mass via the bending of light.  Precise estimates of time-delay of null geodesics were needed and played a pivotal role in their proof. In this paper, we construct an intermediate diagonal metric and make a reduction of this problem to a causality comparison in the compactified spacetimes regarding timelike connectedness near the conformal infinities. This different approach allows us to avoid encountering the difficulties and subtle issues Penrose et al. met. It provides a new, substantially simple, and physically natural non-PDE viewpoint to understand the positive mass theorem. This elementary argument modestly applies to asymptotically flat solutions which are vacuum and stationary near infinity. This is a joint work with Xiaoning Wu and Naqing Xie.

报告人简介：

何孝凯，湖南第一师范学院数学与计算科学学院副教授。2008年获得北京师范大学硕士学位，2013年获中国科学院大学博士学位。2013年-至今在湖南第一师范学院工作。

视频链接：

https://www.bilibili.com/video/BV1DA411V7yR