报告题目：Bulk locality from the celestial amplitude

报告人：张其明 助理教授（清华大学）

报告时间：2021年11月4日（周四）下午13:30-14:30

报告地点：在线报告（腾讯会议ID：610 276 616）

报告摘要：

I will discuss the implications of bulk locality on the celestial amplitude. In the context of the four-point amplitude, the fact that the bulk S-matrix factorizes locally in poles of Mandelstam variables is reflected in the imaginary part of the celestial amplitude. In particular, on the positive real axes in the complex plane of the boost weight, the imaginary part of the celestial amplitude can be given as a positive expansion on the Poincare partial waves, which are nothing but the projection of flat-space spinning polynomials onto the celestial sphere. Furthermore, I will derive the celestial dispersion relation, which relates the imaginary part to the residue of the celestial amplitude for negative even integer boost weight. The latter is precisely the projection of low energy EFT coefficients onto the celestial sphere. I will demonstrate these properties explicitly on the open and closed string celestial amplitudes. 

报告人简介：

张其明，清华大学助理教授。2014年于美国哈佛大学获博士学位，2014年至2019年先后于美国加州大学伯克利分校、戴维斯分校从事博士后研究工作，2019至今任清华大学丘成桐数学科学中心助理教授。

报告链接：

https://www.bilibili.com/video/BV1634y1o7Ef?spm_id_from=333.999.0.0