The spectrum of anomalous magnetohydrodynamics

TL;DR

This paper explores the complex behavior of anomalous magnetohydrodynamics, revealing how high-frequency magnetic currents and low-frequency vortical effects influence plasma dynamics and magnetic field structures.

Contribution

It derives and analyzes the dispersion relations of anomalous MHD, highlighting the interplay of conduction, chiral, and vortical currents across frequency regimes.

Findings

Magnetic currents dominate at high frequencies.

Vortical currents induce large hypermagnetic fields at low frequencies.

Hypermagnetic knots and vortices coexist, indicating complex nonlinear dynamics.

Abstract

The equations of anomalous magnetohydrodynamics describe an Abelian plasma where conduction and chiral currents are simultaneously present and constrained by the second law of thermodynamics. At high frequencies the magnetic currents play the leading role and the spectrum is dominated by two-fluid effects. The system behaves instead as a single fluid in the low-frequency regime where the vortical currents induce potentially large hypermagnetic fields. After deriving the physical solutions of the generalized Appleton-Hartree equation, the corresponding dispersion relations are scrutinized and compared with the results valid for cold plasmas. Hypermagnetic knots and fluid vortices can be concurrently present at very low frequencies and suggest a qualitatively different dynamics of the hydromagnetic nonlinearities.