Effective description of non-equilibrium currents in cold magnetized plasma

TL;DR

This paper develops an effective field theory for cold magnetized plasma that incorporates light charged modes and describes phenomena like pair production and charge accumulation around monopoles.

Contribution

It introduces a new collective mode for electric charges in magnetized plasma, extending traditional force-free electrodynamics with a bosonization approach.

Findings

Scattering of magnetosonic modes produces particles.

Rotating Michel monopole is surrounded by a charge cloud.

The theory captures QED phenomena at the classical level.

Abstract

The dynamics of cold strongly magnetized plasma -- traditionally the domain of force-free electrodynamics -- has recently been reformulated in terms of symmetries and effective field theory, where the degrees of freedom are the momentum and magnetic flux carried by a fluid of cold strings. In physical applications where the electron mass can be neglected one might expect the presence of extra light charged modes -- electrons in the lowest Landau level -- propagating parallel to the magnetic field lines. We construct an effective description of such electric charges, describing their interaction with plasma degrees of freedom in terms of a new collective mode that can be thought of as a bosonization of the electric charge density along each field line. In this framework QED phenomena such as charged pair production and the axial anomaly are described at the classical level. Formally, our construction corresponds to gauging a particular part of the higher form symmetry associated with magnetic flux conservation. We study some simple applications of our effective theory, showing that the scattering of magnetosonic modes generically creates particles and that the rotating Michel monopole is now surrounded by a cloud of electric charge.