Photon radiation by relatively slowly rotating fermions in magnetic field

TL;DR

This paper derives an exact analytical expression for electromagnetic radiation emitted by a slowly rotating charged fermion in a magnetic field, revealing high sensitivity of radiation intensity to the rotation direction and magnitude.

Contribution

It provides a novel analytical solution for synchrotron radiation from a fermion in combined magnetic and rotational motion, highlighting the impact of rotation direction on radiation intensity.

Findings

Radiation intensity is highly sensitive to angular velocity.

Opposite directions of magnetic field and rotation enhance radiation.

The derived formula allows precise calculation of spectral rate and total intensity.

Abstract

We study the electromagnetic radiation by a fermion carrying an electric charge $q$ embedded in a medium rotating with constant angular velocity $\bf\Omega$ parallel or anti-parallel to an external constant magnetic field $\bf B$. We assume that the rotation is "relatively slow"; namely, that the angular velocity $\Omega$ is much smaller than the inverse magnetic length $\sqrt{qB}$. In practice, such angular velocity can be extremely high. The fermion motion is a superposition of two circular motions: one due to its rigid rotation caused by forces exerted by the medium, another due to the external magnetic field. We derive an exact analytical expression for the spectral rate and the total intensity of this type of synchrotron radiation. Our numerical calculations indicate very high sensitivity of the radiation to the angular velocity of rotation. We show that the radiation intensity is strongly enhanced if $q\bf B$ and $\bf \Omega$ point in the opposite directions and is suppressed otherwise.