Thermal chiral vortical and magnetic waves: new excitation modes in chiral fluids

TL;DR

This paper discovers two new heat wave modes in chiral fluids influenced by vortices and magnetic fields, expanding understanding of excitations in systems like quark-gluon plasma and neutron stars.

Contribution

It introduces the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave as new excitation modes in chiral hydrodynamics, with detailed analysis of their properties.

Findings

Identified two new heat wave modes in chiral fluids.

Demonstrated the zero velocity of the chiral vortical wave in full hydrodynamics.

Analyzed frame-dependent effects on wave velocities.

Abstract

In certain circumstances, chiral (parity-violating) medium can be described hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible examples of such systems include strongly coupled quark-gluon plasma, liquid helium 3He-A, neutron stars and the Early Universe. We study first-order hydrodynamics of a chiral fluid on a vortex background and in an external magnetic field. We show that there are two previously undiscovered modes describing heat waves propagating along the vortex and magnetic field. We call them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also identify known gapless excitations of density (chiral vortical and chiral magnetic waves) and transverse velocity (chiral Alfven wave). We demonstrate that the velocity of the chiral vortical wave is zero, when the full hydrodynamic framework is applied, and hence the wave is absent and the excitation reduces to the charge diffusion mode. We also comment on the frame-dependent contributions to the obtained propagation velocities.