# Properties of Dual Supertranslation Charges in Asymptotically Flat Spacetimes

## TL;DR

This paper investigates the properties and symmetries of dual supertranslation charges in asymptotically flat spacetimes, revealing their topological nature and physical relevance through non-vanishing examples and dynamical processes.

## Contribution

It introduces and analyzes dual supertranslation charges, demonstrating their symmetry properties, topological invariance, and physical significance in gravitational contexts.

## Key findings

- Dual supertranslation charges are topological and invariant under smooth metric variations.
- Certain spacetimes exhibit non-zero dual supertranslation charges.
- Dynamical processes can change the values of these charges across regions.

## Abstract

We study several properties of some new charges of asymptotically flat spacetimes. These dual supertranslation charges are akin to the magnetic large $U(1)$ charges in QED. In this paper we find the symmetries associated with these charges and show that the global dual supertranslation charge is topological because it is invariant under globally defined, smooth variations of the asymptotic metric. We also exhibit spacetimes where the charge does not vanish and we find dynamical processes that interpolate between regions with different values of these charges.