Phys. Rev. D, 109, 065022 (2024)

Near horizon linearized gravity and soft theorem

Pujian Mao, Kai-Yu Zhang and Bochen Zhou

Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 135 Yaguan Road, Tianjin 300350, China.

* pjmao@tju.edu.cn, kaiyu_zhang@tju.edu.cn, zhoubch@tju.edu.cn

Abstract

In this paper, we study the linearized gravity theory in the near horizon region of the Schwarzschild black hole in four dimensional spacetime. Under the Newman-Unti gauge, we derive the most general near horizon symmetry and solution space without any near horizon fall-off condition. There are four towers of surface charges that are generic functions on the horizon associated to the near horizon symmetry. With suitable near horizon fall-off conditions, we reveal a soft graviton theorem from the Ward identity of the near horizon supertranslation in both coordinates space and momentum space.