Asymptotic perfect fluid dynamics as a consequence of AdS/CFT

TL;DR

The paper investigates the late-time evolution of strongly coupled gauge-theory matter in a boost-invariant setting using AdS/CFT and holographic renormalization. By solving the nonlinear Einstein equations in Fefferman-Graham coordinates and enforcing bulk nonsingularity, it shows that perfect-fluid hydrodynamics emerges as the unique asymptotic boundary behavior, interpreted as a moving black hole in AdS_5. The analysis demonstrates that, among power-law decays f(τ) ~ τ^{-s}, only s=4/3 yields a nonsingular bulk, thereby providing a gravity-side justification for Bjorken-like perfect-fluid dynamics in the strongly coupled regime. The work also outlines avenues for incorporating subleading viscous effects and relaxing symmetry assumptions to extend the framework to more general heavy-ion collision scenarios.

Abstract

We study the dynamics of strongly interacting gauge-theory matter (modelling quark-gluon plasma) in a boost-invariant setting using the AdS/CFT correspondence. Using Fefferman-Graham coordinates and with the help of holographic renormalization, we show that perfect fluid hydrodynamics emerges at large times as the unique nonsingular asymptotic solution of the nonlinear Einstein equations in the bulk. The gravity dual can be interpreted as a black hole moving off in the fifth dimension. Asymptotic solutions different from perfect fluid behaviour can be ruled out by the appearance of curvature singularities in the dual bulk geometry. Subasymptotic deviations from perfect fluid behaviour remain possible within the same framework.

Figures (1)

• Figure 1: The curvature scalar ${\mathfrak R^2}$ calculated as a function of $w=v/\Delta(s)^{1/4}$ for the perfect fluid case $s=4/3$ (solid line), $s=4/3-0.1$ (dotted line) and $s=4/3+0.2$ (dashed line).