Subleading Soft Theorem for Multiple Soft Gravitons

TL;DR

This paper derives the subleading soft graviton theorem applicable to multiple soft gravitons in quantum gravity, valid across various dimensions and energy states, with specific considerations for loop contributions in lower dimensions.

Contribution

It provides a general derivation of the subleading soft graviton theorem for multiple soft gravitons in arbitrary quantum gravity theories, including all orders in perturbation theory for dimensions six or higher.

Findings

Valid for all orders in perturbation theory in six or more dimensions.

Tree-level results applicable for five or fewer dimensions.

Addresses infrared contributions in loop amplitudes for lower dimensions.

Abstract

We derive the subleading soft graviton theorem in a generic quantum theory of gravity for arbitrary number of soft external gravitons and arbitrary number of finite energy external states carrying arbitrary mass and spin. Our results are valid to all orders in perturbation theory when the number of non-compact space-time dimensions is six or more, but only for tree amplitudes for five or less non-compact space-time dimensions due to enhanced contribution to loop amplitudes from the infrared region.