Residual Local Supersymmetry and the Soft Gravitino

TL;DR

This paper uncovers an infinite set of fermionic symmetries in four-dimensional supergravity, linking them to soft gravitino limits and supersymmetry at all angles, and extends BMS symmetries to include supersymmetry.

Contribution

It demonstrates the existence of an infinite tower of fermionic symmetries in supergravity and their relation to soft gravitino theorems and BMS group extensions.

Findings

Fermionic symmetries correspond to soft gravitino limits.

Charges commute with BMS translations, extending BMS symmetry.

Supersymmetry is realized at every angle in asymptotically flat spacetime.

Abstract

We show that there exists an infinite tower of fermionic symmetries in pure $d=4$, $\mathcal{N}=1$ supergravity on an asymptotically flat background. The Ward identities associated with these symmetries are equivalent to the soft limit of the gravitino and to the statement of supersymmetry at every angle. Additionally, we show that these charges commute into charges associated with the (unextended) BMS group, providing a supersymmetrization of the BMS translations.