Schwinger-Keldysh effective action for relativistic Brownian particle in AdS-CFT

TL;DR

This paper derives the Schwinger-Keldysh effective action for a relativistic heavy quark in a strongly coupled plasma using holography, revealing nonlinear fluctuation-dissipation relations and cubic interactions induced by velocity.

Contribution

It introduces a holographic computation of the effective action including cubic interactions and nonlinear fluctuation-dissipation relations for a relativistic quark in plasma.

Findings

Effective action includes cubic interactions induced by velocity.

Nonlinear fluctuation-dissipation relations are established.

Holographic dual involves a noisy trailing string in Schwarzschild-AdS5.

Abstract

We compute Schwinger-Keldysh effective action for a relativistic heavy quark (with constant background velocity) in strongly coupled N = 4 supersymmetric Yang-Mills plasma. The holographic dual description involves a noisy trailing string moving in Schwarzschild-AdS5 black brane. The noise is caused by Hawking radiation emitted from string worldsheet horizon. Besides quadractic terms, the effective action contains cubic interactions, which are entirely induced by the constant background velocity. The nonlinear fluctuation-dissipation relations for three-point functions are discussed based on holographic results.