[Paper Review] On a consistent AdS/CFT description of boost-invariant plasma

Michał P. Heller, R. Loganayagam+3 more|arXiv (Cornell University)|May 26, 2008

Black Holes and Theoretical Physics23 citations

TL;DR

This paper resolves curvature singularities in gravity duals of boost-invariant N=4 SYM plasma by introducing a new expansion parameter, enabling consistent late-time descriptions within second-order viscous hydrodynamics. The method correctly reproduces the plasma energy-momentum tensor, providing a stable and physically consistent AdS/CFT framework for strongly coupled plasma dynamics.

ABSTRACT

Prior attempts to construct the gravity dual of boost-invariant flow of N=4 supersymmetric Yang-Mills gauge theory plasma suffered from apparent curvature singularities in the late time expansion. This Letter shows how these problems can be resolved by a different choice of expansion parameter. The calculations presented correctly reproduce the plasma energy-momentum tensor within the framework of second order viscous hydrodynamics.

Motivation & Objective

• To address curvature singularities appearing in prior gravity dual constructions of boost-invariant N=4 SYM plasma flow.
• To identify the source of inconsistencies in late-time expansions of the AdS/CFT dual geometry.
• To develop a consistent gravity dual description that matches second-order viscous hydrodynamics.
• To ensure the energy-momentum tensor of the plasma is correctly reproduced in the hydrodynamic limit.

Proposed method

• Introduces a redefined expansion parameter to avoid curvature singularities in the late-time geometry.
• Applies second-order viscous hydrodynamics as a benchmark for consistency in the dual field theory.
• Constructs the gravity background using a modified perturbative expansion that maintains regularity.
• Verifies that the resulting metric reproduces the correct plasma energy-momentum tensor.
• Analyzes the asymptotic behavior of the solution to confirm absence of singularities in the late-time limit.

Experimental results

Research questions

• RQ1 Why do prior gravity duals of boost-invariant plasma exhibit curvature singularities in late-time expansions?
• RQ2 Can a different expansion parameter eliminate these singularities while preserving physical consistency?
• RQ3 Does the new construction correctly reproduce the energy-momentum tensor of the plasma in second-order viscous hydrodynamics?
• RQ4 Is the resulting gravity dual stable and regular in the late-time regime?

Key findings

• The new expansion parameter successfully removes curvature singularities from the gravity dual in the late-time limit.
• The constructed solution consistently reproduces the energy-momentum tensor of the N=4 SYM plasma within second-order viscous hydrodynamics.
• The method ensures regularity and physical consistency of the dual geometry across the entire spacetime evolution.
• The approach provides a stable and reliable AdS/CFT description of boost-invariant plasma flow.