Primordial magnetic field and kinetic theory with Berry curvature

TL;DR

This paper investigates how chiral imbalance in the early universe's plasma can generate primordial magnetic fields using Berry-curvature modified kinetic theory, providing estimates consistent with current observational bounds.

Contribution

It introduces a novel application of Berry-curvature kinetic theory to model magnetic field generation in the early universe's plasma at high temperatures.

Findings

Generated magnetic fields of order 10^{27} Gauss at T~80 TeV

Magnetic field strength can reach 10^{31} Gauss in certain regimes

Results align with observational constraints on primordial magnetic fields

Abstract

We study the generation of magnetic field in the primordial plasma of the standard model (SM) particles at temperature $T>80$~TeV much higher than the electroweak scale. It is assumed that there is an excess number of right-handed electrons over left-handed positrons in the plasma. Using the Berry-curvature modified kinetic theory to incorporate the effect of the Abelian anomaly, we show that this chiral-imbalance leads to generation of hyper-magnetic field in the plasma in both the collision dominated and the collisionless regimes. It is shown that in the collision dominated regime the chiral-vorticity effect can generate finite vorticity in the plasma together with the magnetic field. Typical strength of the generated magnetic field is $10^{27}$~Gauss at $T\sim 80$~TeV with the length scale $10^5/T$ whereas the Hubble length scale is $10^{13}/T$. Further the instability can also generate the magnetic field of order $10^{31}$~Gauss at typical length scale $10/T$. But there may not be any vorticity generation in this regime. We show that the estimated values of the magnetic field are consistent with the bounds obtained from present observations.