# N=4 Supersymmetric BMS3 algebras from asymptotic symmetry analysis

## TL;DR

This paper derives the N=4 super BMS3 algebra from three-dimensional flat supergravity, revealing its structure as a flat limit of AdS supergravity and analyzing supersymmetry bounds and Killing spinors.

## Contribution

It explicitly constructs the asymptotic symmetry algebra for N=4 flat supergravity and connects it to the AdS supergravity limit, enhancing understanding of supersymmetric asymptotic symmetries.

## Key findings

- Derived the N=4 super BMS3 algebra from flat supergravity.
- Connected the algebra to the AdS supergravity limit.
- Analyzed supersymmetry bounds and Killing spinors.

## Abstract

We consider three dimensional $N=4$ flat supergravity, with an abelian R-symmetry enhancing the gravitational phase space. We obtain the field configuration whose asymptotic symmetries at null infinity coincide with the centrally extended $N=4$ super Bondi-Metzner-Sachs (BMS) algebra .The killing spinors for this generic configuration are obtained together with the energy bounds imposed by supersymmetry. It is explicitly shown that the same algebra can be obtained as a flat (AdS radius $\rightarrow \infty$ ) limit of the combined $(2,0)$ and $(0,2)$ sectors of AdS supergravity.