Linear Newman-Penrose charges as subleading BMS and dual BMS charges

TL;DR

This paper extends the understanding of asymptotic charges in flat spacetimes by developing a comprehensive framework for subleading and dual BMS charges, connecting them to Newman-Penrose charges and analyzing their conservation properties.

Contribution

It provides a complete all-orders expansion of subleading BMS and dual BMS charges, linking them to Newman-Penrose charges and explaining their symmetry and conservation properties.

Findings

Infinite tower of Newman-Penrose charges originates from asymptotic symmetries.

Charges are not conserved at the non-linear level.

Charges do not exhibit full supertranslation invariance at linear order.

Abstract

In this paper, we further develop previous work on asymptotically flat spacetimes and extend subleading BMS and dual BMS charges in a large $r$ expansion to all orders in $r^{-1}$. This forms a complete account of this prescription in relation to the previously discovered Newman-Penrose charges. We provide an explanation for the origin of the infinite tower of linear Newman-Penrose charges with regards to asymptotic symmetries and justify why these charges fail to be conserved at the non-linear level as well as failing to exhibit full supertranslation invariance even at the linear level.