JHEP, 01, 044 (2024)

Soft theorems in de Sitter spacetime

Pujian Mao and Kai-Yu Zhang

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

Abstract

In this paper, we derive a soft photon theorem and a soft gluon theorem in the de Sitter spacetime from the Ward identity of the near cosmological horizon large gauge transformation. Taking the flat limit of the de Sitter spacetime, the soft theorems naturally recover the corresponding flat spacetime soft theorems.