Kaluza-Klein reduction of relativistic fluids and their gravity duals

TL;DR

This paper explores the hydrodynamics of relativistic fluids with multiple conserved charges through Kaluza-Klein reduction, linking it to black brane gravity duals and deriving their equations of state and transport properties.

Contribution

It introduces a method to derive the hydrodynamics of charged fluids from higher-dimensional neutral fluids via Kaluza-Klein reduction, extending fluid/gravity correspondence.

Findings

Derived equations of state and transport coefficients for charged fluids.

Connected fluid dynamics to Kaluza-Klein black brane gravity duals.

Provided a framework for analyzing multi-charge relativistic fluids.

Abstract

We study the hydrodynamics of relativistic fluids with several conserved global charges (i.e., several species of particles) by performing a Kaluza-Klein dimensional reduction of a neutral fluid on a N-torus. Via fluid/gravity correspondence, this allows us to describe the long-wavelength dynamics of black branes with several Kaluza-Klein charges. We obtain the equation of state and transport coefficients of the charged fluid directly from those of the higher-dimensional neutral fluid. We specialize these results for the fluids dual to Kaluza-Klein black branes.