# The BMS4 algebra at spatial infinity

## TL;DR

This paper demonstrates that the BMS4 algebra naturally arises as the asymptotic symmetry at spatial infinity and aligns with Strominger's BMS4 symmetry of the S-matrix, using linearised theory.

## Contribution

It establishes the connection between the BMS4 algebra at spatial infinity and Strominger's BMS4 symmetry of the S-matrix, clarifying their relationship.

## Key findings

- BMS4 algebra appears at spatial infinity as an asymptotic symmetry.
- The linearised theory confirms the BMS4 algebra matches Strominger's S-matrix symmetry.
- The work links spatial infinity symmetries with scattering matrix symmetries.

## Abstract

We show how a global BMS4 algebra appears as the asymptotic symmetry algebra at spatial infinity. Using linearised theory, we then show that this global BMS4 algebra is the one introduced by Strominger as a symmetry of the S-matrix.