Recombination era magnetic fields from axion dark matter

Abstract

We introduce a new mechanism for generating magnetic fields in the recombination era. This Harrison-like mechanism utilizes vorticity in baryons that is sourced through the Bose-Einstein condensate of axions via gravitational interactions. The magnetic fields generated are on the galactic scales $\sim 10\mathrm{kpc}$ and have a magnitude of the order of $B\sim 10^{-23}\mathrm{G}$ today. The field has a greater magnitude than those generated from other mechanisms relying on second order perturbation theory, and is sufficient to provide a seed for battery mechanisms.

4 pages; v2: minor changes, references added

References in corpus (8)

• Bose-Einstein Condensation of Dark Matter Axions
• On the Origin of Cosmic Magnetic Fields
• A Concise Introduction to Perturbation Theory in Cosmology
• Can cosmological perturbations produce early universe vorticity?
• Cosmological Structure Formation Creates Large-Scale Magnetic Fields
• Estimating the amount of vorticity generated by cosmological perturbations in the early universe
• A further look at particle annihilation in dark matter caustics
• Effects of non-linearities on magnetic field generation

Cited by in corpus (2)

• The Gamma-Ray Window to Intergalactic Magnetism
• Primordial magnetogenesis before recombination