On asymptotic symmetries in higher dimensions for any spin

TL;DR

This paper extends the study of asymptotic symmetries to higher-dimensional flat spacetimes for any spin, identifying new symmetries and linking them to soft theorems and partially-massless representations.

Contribution

It generalizes the concept of extended BMS symmetries to higher dimensions and higher spins, establishing a correspondence with partially-massless representations on the celestial sphere.

Findings

Identified higher-spin supertranslations and superrotations in dimensions ≥4.

Linked supertranslations to Weinberg's soft theorem in even dimensions.

Provided a framework for defining asymptotic charges in higher-dimensional spacetimes.

Abstract

We investigate asymptotic symmetries in flat backgrounds of dimension higher than or equal to four. For spin two we provide the counterpart of the extended BMS transformations found by Campiglia and Laddha in four-dimensional Minkowski space. We then identify higher-spin supertranslations and generalised superrotations in any dimension. These symmetries are in one-to-one correspondence with spin-$s$ partially-massless representations on the celestial sphere, with supertranslations corresponding in particular to the representations with maximal depth. We discuss the definition of the corresponding asymptotic charges and we exploit the supertranslational ones in order to prove the link with Weinberg's soft theorem in even dimensions.