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arXiv · 1507.03001

Recombination era magnetic fields from axion dark matter

Nilanjan Banik·Adam J. Christopherson
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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 $\sim 10\,{\rm kpc}$ and have a magnitude of the order of $B\sim10^{-23}\,{\rm G}$ 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.

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Nilanjan Banik, Adam J. Christopherson. 2015-07-10. Recombination era magnetic fields from axion dark matter. https://doi.org/10.1103/physrevd.93.043003

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