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 ${\mathrm{AdS}}_4$ black branes possess a special class of approximate supertranslations (which we identify).

中文翻译：

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黑洞超平移和流体动力学熵

我们研究了 AdS 黑膜的近似地平线对称性与它们的双重流体动力学描述中的近似守恒流之间的关系。我们认为，存在一个近似守恒的熵流是独一无二的$2+1$维流体流动意味着${\mathrm{广告}}_4$黑膜拥有一类特殊的近似超平移（我们确定）。