A novel supersymmetric extension of BMS symmetries at null infinity

TL;DR

This paper introduces a new supersymmetric extension of BMS symmetries at null infinity by combining BMS vector fields with BMS twistors, resulting in a superalgebra that includes Lorentz transformations and relates to string theory symmetries.

Contribution

The authors construct a novel supersymmetric BMS algebra that incorporates Lorentz transformations and connects to Neveu-Schwarz supersymmetries, expanding the understanding of symmetries at null infinity.

Findings

Superalgebra includes all BMS vector fields and Lorentz transformations.

Existence of a projection to Neveu-Schwarz supersymmetries on a 2-sphere.

Comparison with supergravity-based supersymmetric BMS extensions.

Abstract

We show that we can combine the (complex, self-dual) BMS vector fields with the recently defined BMS twistors to obtain a new supersymmetric extension of the BMS symmetries at null infinity. We compare our construction to other supersymmetric extensions of the BMS algebra proposed in the context of supergravity. Unlike the standard constructions the anticommutator in our superalgebra generates all the BMS vector fields including the Lorentz transformations. We also show that there exists a projection from our BMS Lie superalgebra to the global subalgebra of the Neveu-Schwarz supersymmetries on a 2-sphere, which are commonly considered in string theory and 2-dimensional conformal field theory.