Radiation of a circulating quark in strongly coupled N=4 super Yang-Mills theory

TL;DR

This paper uses gauge/gravity duality to analyze the radiation pattern of a circulating quark in strongly coupled N=4 SYM theory, revealing similarities to classical synchrotron radiation with specific angular and radial characteristics.

Contribution

It provides the first detailed computation of radiation emitted by a circulating quark in strongly coupled SYM theory using holography, highlighting qualitative similarities to classical electrodynamics.

Findings

Radiation is emitted in a narrow beam at high velocities.

The opening angle of radiation scales as 1/γ.

Radial thickness of the radiation scales as 1/γ^3.

Abstract

The energy density and angular distribution of power radiated by a quark undergoing circular motion in strongly coupled ${\cal N}=4$ supersymmetric Yang-Mills (SYM) theory is computed using gauge/gravity duality. The results are qualitatively similar to that of synchrotron radiation produced by an electron in circular motion in classical electrodynamics: At large velocities the quark emits radiation in a narrow beam along its velocity vector with a characteristic opening angle $\alpha \sim 1/\gamma$ and radial thickness scaling like $\sim 1/\gamma^3$.