Particle temperature and the Chiral Vortical Effect in the early universe

TL;DR

This paper investigates how particle temperature variations influence the chiral magnetic field evolution in the early universe, revealing temperature-dependent effects on magnetic turbulence and spectral skewness.

Contribution

It introduces the temperature-dependent chiral vortical effect into early universe magnetic field evolution and links non-Gaussian spectral features to particle temperature differences.

Findings

No change in magnetic energy spectrum at large scales.

In the Kolmogorov regime, the magnetic spectrum peak becomes negatively skewed.

The skewed peak fits a beta distribution, indicating turbulence influence.

Abstract

We study the effect of hotter or colder particles on the evolution of the chiral magnetic field in the early universe. We are interested in the temperature dependent term in the chiral vortical effect. There are no changes in the magnetic energy spectrum at large lengthscales but in the Kolmogorov regime we do find a difference. Our numerical results show that the Gaussian peak in the magnetic spectrum becomes negatively skewed. The negatively skewed peak can be fitted with a beta distribution. Analytically one can relate the non-Gaussianity of the distribution to the temperature dependent vorticity term. The vorticity term is therefore responsible for the beta distribution in the magnetic spectrum. Since the beta distribution has already been used to model turbulent dispersion in fluids, hence it seems that the presence of hotter or colder particles may lead to turbulence in the magnetized plasma.