Thermalization of Strongly Coupled Field Theories

TL;DR

This paper investigates how strongly coupled field theories thermalize after a quench using holographic methods, revealing that entanglement entropy governs the slowest thermalization and that UV regions thermalize first.

Contribution

It provides a detailed analysis of the scale-dependent thermalization process in strongly coupled theories using AdS/CFT, including the behavior of entanglement entropy, Wilson loops, and two-point functions.

Findings

Entanglement entropy sets the thermalization timescale.

UV regions thermalize before IR regions.

Entanglement growth saturates a causality bound.

Abstract

Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench via saddlepoint calculations of 2-point functions, Wilson loops and entanglement entropy in $d=2,3,4$. For homogeneous initial conditions, the entanglement entropy thermalizes slowest, and sets a timescale for equilibration that saturates a causality bound. The growth rate of entanglement entropy density is nearly volume-independent for small volumes, but slows for larger volumes. In this strongly coupled setting, the UV thermalizes first.