Thermalization of Strongly Coupled Field Theories

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.