报告题目：Quantum geometry and effective dynamics of Janis-Newman-Winicour singularities 

报告人：张向东  教授（华南理工大学）

报告时间：2020 年 12 月 17 日（周四）15：30          

报告地点：在线报告（ 腾讯会议 ID : 537 4946 4937）

报告摘要：

In this talk we will investigate the effective dynamics of the loop quantized Janis-Newman-Winicour(JNW) spacetime which is an extension of the Schwarzschild spacetime with an extra minimally coupled massless scalar field. Two parameters are  introduced in order to regularize the Hamiltonian constraint in the quantum effective dynamics. These two parameters are assumed to be Dirac observables when the effective dynamics is solved. By carefully choosing appropriate conditions for these two parameters, we completely determine them, and the resulted new effective description of the JNW spacetime leads to a well behaved quantum dynamics which on one hand resolves the classical singularities, and on the other hand, agrees with the classical dynamics in the low curvature region.

报告人简介：张向东，华南理工大学教授。2012年7月博士毕业于北京师范大学。曾任德国埃尔朗根大学访问学者（2014.11-2015.11），华南理工大学讲师(2012.07-2013.10)，副教授（2013.10-2016.3），教授(2016.04 - 至今)。目前主要研究兴趣包括：圈量子引力及其宇宙学应用；黑洞相关的物理效应等。主持两项国家自然科学基金基金项目。截止目前已在PRL，PRD，EPJC等物理学著名期刊发表研究论文30余篇。

代表作：

【1】     Xiangdong Zhang and Yongge Ma, Extension of loop quantum gravity to f(R) theories, Phys. Rev. Lett. 106, 171301 (2011).
【2】     Cong Zhang and Xiangdong Zhang，Quantum geometry and effective dynamics of Janis-Newman-Winicour singularities，Phys. Rev. D 101, 086002 (2020).
【3】     Cong Zhang, Yongge Ma, Shupeng Song, and Xiangdong Zhang, Loop quantum Schwarzschild interior and black hole remnant, Phys. Rev. D 102, 041502(R) (2020).
【4】     Songming Zhang, Yunlong Liu, and Xiangdong Zhang, Kerr–de Sitter and Kerr–anti–de Sitter black holes as accelerators for spinning particles, Phys. Rev. D 99, 064022 (2019).