Heavy quark in an expanding plasma in AdS/CFT

TL;DR

This paper derives a Langevin equation for a heavy quark in an expanding, out-of-equilibrium plasma using AdS/CFT, analyzing both stationary and moving quark cases with computed two-point functions.

Contribution

It introduces a novel Langevin framework for heavy quarks in an expanding plasma via the Janik-Peschanski dual, extending previous static analyses.

Findings

Langevin equation for heavy quark in expanding plasma derived

Two-point functions for noise in expanding plasma computed

Analysis includes both stationary and moving quark scenarios

Abstract

Using the Janik-Peschanski dual to a Bjorken flow, a Langevin equation is derived for a heavy quark in an expanding N = 4 supersymmetric Yang-Mills plasma. Such a plasma is characterized by a proper-time dependence of the temperature and corresponds to a system out of equilibrium. The analysis first focuses on a quark at rest in the plasma comoving frame. The case of a quark moving across a longitudinally expanding plasma is then considered. The two-point functions for the random noise acting on such heavy quark probes are computed.