# nLab soft graviton theorem

Contents

### Context

#### Gravity

gravity, supergravity

# Contents

## Idea

In perturbative quantum gravity, the soft graviton theorem (Weinberg 65) re-formulates scattering amplitudes of a set of finite energy external particles with one or more low energy external gravitons, in terms of the amplitude without the low energy gravitons.

In the classical limit, there is a different manifestation of the same theorem (Saha-Sahoo-Sen 19): here it determines the low frequency component of the gravitational wave-form produced during a scattering process in terms of the momenta and spin of the incoming and outgoing objects, without any reference to the interactions responsible for the scattering.

## References

Original reference:

Review with focus on photons in electromagnetism:

• Noah Miller, From Noether’s Theorem to Bremsstrahlung: a pedagogical introduction to large gauge transformations and classical soft theorems (arXiv:2112.05289)

• Arnab Priya Saha, Biswajit Sahoo, Ashoke Sen, Proof of the Classical Soft Graviton Theorem in $D=4$ (arXiv:1912.06413)