Reheating chiral dynamos with spin-0 and massive spin-1 torsions via chiral asymmetry

TL;DR

This paper investigates how constant torsion in the early universe influences chiral asymmetry and magnetic field generation, revealing that torsion can significantly amplify primordial magnetic fields and affect cosmic magnetogenesis.

Contribution

It introduces the novel idea of constant torsion's impact on chiral physics and magnetic field amplification in cosmology, expanding understanding of early universe magnetogenesis.

Findings

Weak magnetic fields are boosted by torsionful dynamo effects.

Torsion of 1 MeV can generate magnetic fields of 10^{-9} Gauss today.

Reheating dynamo processes can regenerate decaying cosmic magnetic fields.

Abstract

Recently, Syderenko et al. (JCAP, 10: 018, 2016) investigated magnetogenesis and chiral asymmetry in the early hot universe. This study explores the impact of minimally coupling a constant torsion in their cosmological model, suggesting new chiral physics. Physically, this means that if torsion is right chiral, the difference between the number of right and left chiralities does not change. Moreover, the decay of chiral asymmetry depends on torsion chirality. We solve the chiral torsionful dynamo equation for magnetic field seeds. Magnetic helical fields are considered important for chiral fermion asymmetry. Even in $(3+1)$ dimensional spacetime, torsion is highly suppressed beyond inflation (Eur Phys J C 82: 291, 2022). However, torsion of $1\,\mathrm{MeV}$ appears in the early universe. Equations for correlated magnetic field coefficients are solved in terms of torsion. Weak magnetic fields of the order of $10^{-42}$ Gauss are boosted by powerful torsionful dynamo amplification, generating a much stronger magnetic field of the order of $10^{-9}$ Gauss in the present universe. A galactic magnetic field of $10^{-6}$ Gauss in the present universe, with torsion of $10^{-15}$ Gauss, leads us to a galactic dynamo seed of $10^{-9}$ Gauss. We also discuss reheating dynamo regeneration of decaying cosmic magnetic fields during the hadronization era. The relation between the reheating contribution to e-folds and the connection between CMF and temperature squared allows us to obtain dynamo amplification in terms of N-folds of inflation. The main innovation of this work is the exploration of constant torsion in a cosmological model, revealing new chiral physics. This study offers a new perspective on the origin and evolution of magnetic fields in the early universe.