Leptogenesis and Primordial Magnetic Fields

TL;DR

This paper explores how leptogenesis can generate primordial magnetic fields with specific helicities, which evolve over time and can be observed today, offering insights into early universe physics beyond the Standard Model.

Contribution

It demonstrates that leptogenesis produces right-handed helical magnetic fields, contrasting with left-handed fields from electroweak baryogenesis, and discusses their evolution and observational implications.

Findings

Leptogenesis generates right-handed helical magnetic fields.

Magnetic fields evolve to astrophysically relevant scales and strengths.

Observations can probe physics beyond the Standard Model.

Abstract

The anomalous conversion of leptons into baryons during leptogenesis is shown to produce a right-handed helical magnetic field; in contrast, the magnetic field produced during electroweak baryogenesis is known to be left-handed. If the cosmological medium is turbulent, the magnetic field evolves to have a present day coherence scale and field strength that are of astrophysical interest. Observations of the amplitude, coherence scale, and helicity of the intergalactic magnetic field promise to provide a powerful probe of physics beyond the Standard Model and the very early universe.