Abstract
We propose a mechanism generating primordial magnetic fields after the annihilations. Our mechanism involves an ultralight axionlike particle (ALP) which constitutes the dark matter and a dark gauge boson introduced to bypass the obstacle placed by the conductivity of cosmic plasma. In our scheme, a coherently oscillating ALP amplifies the dark photon field, and part of the amplified dark photon field is concurrently converted to the ordinary magnetic field through the ALP-induced magnetic mixing. For the relevant ALP mass range , our mechanism can generate with a coherent length , which is large enough to provide a seed of the galactic magnetic fields. The mechanism also predicts a dark electromagnetic field , which can result in interesting astrophysical or cosmological phenomena by inducing the mixings between the ALP, ordinary photon, and dark photon states.
- Received 12 March 2018
- Revised 18 May 2018
DOI:https://doi.org/10.1103/PhysRevLett.121.031102
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.
Published by the American Physical Society