Weak and strong coupling equilibration in nonabelian gauge theories

Understand

We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up.

• The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow.
• This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate.
• We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.