Holographic Wilsonian renormalization of a heavy quark moving through a strongly coupled plasma

TL;DR

This paper develops a holographic Wilsonian renormalization approach to derive an effective string action for a heavy quark in a strongly coupled plasma, revealing how IR physics encodes UV information and enabling improved semi-holographic modeling.

Contribution

It introduces a holographic Wilsonian RG method to obtain an effective string action for heavy quarks, connecting IR cutoff dependence with UV data in holographic duals.

Findings

The effective action depends only on the IR geometry between the horizon and cutoff.

RG flow equations for the effective action coefficients are derived.

The quark's force is shown to be independent of the cutoff position.

Abstract

A heavy quark moving through a strongly coupled deconfined plasma has a holographic dual description as a string moving in a black brane geometry. We apply the holographic Wilsonian renormalization method to derive a holographic effective string action dual to the heavy quark. The effective action only depends on the geometry between the black brane horizon and a cutoff localized in the radial direction, corresponding to the IR of the dual theory. We derive RG flow equations for the coefficients in the effective action and show that the force acting on the heavy quark is independent of the position of the cutoff. All the information about the UV is hidden in integration constants of the RG flow equations. This type of approach could be used to improve semi-holographic models where the UV is described by perturbative QCD and the IR by a holographic model.