Black Holes as Lumps of Fluid

TL;DR

This paper explores a duality between black holes and fluid lumps, analyzing their stability, phases, and properties, and suggests a fluid description for black holes in large dimensions, with detailed comparisons and new insights.

Contribution

It clarifies the fluid-black hole duality, investigates phase structures, and connects fluid instabilities to black hole instabilities, extending the understanding of black hole physics through fluid dynamics.

Findings

Fluid instability corresponds to black string Gregory-Laflamme instability

Fluid phases match black hole solutions in asymptotically flat spacetime

Large dimension limit suggests fluid description for black holes

Abstract

The old suggestive observation that black holes often resemble lumps of fluid has recently been taken beyond the level of an analogy to a precise duality. We investigate aspects of this duality, and in particular clarify the relation between area minimization of the fluid vs. area maximization of the black hole horizon, and the connection between surface tension and curvature of the fluid, and surface gravity of the black hole. We also argue that the Rayleigh-Plateau instability in a fluid tube is the holographic dual of the Gregory-Laflamme instability of a black string. Associated with this fluid instability there is a rich variety of phases of fluid solutions that we study in detail, including in particular the effects of rotation. We compare them against the known results for asymptotically flat black holes finding remarkable agreement. Furthermore, we use our fluid results to discuss the unknown features of the gravitational system. Finally, we make some observations that suggest that asymptotically flat black holes may admit a fluid description in the limit of large number of dimensions.