On black hole supertranslations and hydrodynamic enstrophy

TL;DR

This paper explores the connection between near-symmetries of AdS black branes and conserved quantities in dual hydrodynamics, revealing a unique supertranslation symmetry linked to enstrophy in 2+1 dimensions.

Contribution

It identifies a novel class of approximate supertranslations in AdS${}_4$ black branes associated with enstrophy conservation in 2+1D fluid flow.

Findings

Existence of an approximately conserved enstrophy current in 2+1D fluids.

Identification of a special class of approximate supertranslations in AdS${}_4$ black branes.

Link between horizon symmetries and hydrodynamic conserved quantities.

Abstract

We study the relation between approximate horizon symmetries of AdS black branes and approximately conserved currents in their dual hydrodynamic description. We argue that the existence of an approximately conserved enstrophy current unique to $2+1$ dimensional fluid flow implies that AdS${}_4$ black branes possess a special class of approximate supertranslations (which we identify).