# New dual gravitational charges

## TL;DR

This paper uncovers an infinite set of new dual supertranslation charges at null infinity, expanding the known BMS symmetry algebra by identifying their relation to the Newman-Penrose formalism.

## Contribution

It introduces a novel method to derive dual supertranslation charges by dualising Barnich-Brandt asymptotic charges, revealing previously unknown symmetries.

## Key findings

- Discovery of an infinite set of dual supertranslation charges.
- Identification of these charges as duals to known BMS supertranslations.
- Connection of these charges to the imaginary part of the leading Newman-Penrose scalar c9_2.

## Abstract

We show that there are a further infinite number of, previously unknown, supertranslation charges. These can be viewed as duals of the known BMS charges corresponding to supertranslations. In Newman-Penrose language, these new supertranslation charges roughly correspond to the imaginary part of the leading term in $\psi_2$. We find these charges by dualising the Barnich-Brandt asymptotic charges and argue that this prescription gives rise to new bona fide charges at null infinity.