# Infinite towers of supertranslation and superrotation memories

## TL;DR

This paper develops a comprehensive framework for gravitational memory effects, revealing infinite towers of such effects linked to supertranslation and superrotation symmetries, and connects them to conservation laws and soft graviton theorems.

## Contribution

It introduces a new structure for gravitational memory effects consistent with electric-magnetic duality, including infinite towers and their relation to symmetries and conservation laws.

## Key findings

- Matter-induced transitions generate infinite memory towers.
- Memory effects correspond to conservation laws at spatial infinity.
- Supertranslations and superrotations relate to displacement memory effects.

## Abstract

A framework that structures the gravitational memory effects and which is consistent with gravitational electric-magnetic duality is presented. A correspondence is described between memory observables, particular subleading residual gauge transformations, associated overleading gauge transformations and their canonical surface charges. It is shown that matter-induced transitions can generate infinite towers of independent memory effects at null infinity. These memories are associated with an infinite number of conservation laws at spatial infinity which lead to degenerate towers of subleading soft graviton theorems. It is shown that the leading order mutually commuting supertranslations and (novel) superrotations are both associated with a leading displacement memory effect, which suggests the existence of new boundary conditions.