Eur. Phys. J. C (2015) 75: 397
https://doi.org/10.1140/epjc/s10052-015-3606-3

Regular Article - Theoretical Physics

Axion production and CMB spectral distortion in cosmological tangled magnetic field

¹ Theory group, INFN Laboratori Nazionali del Gran Sasso, 67100, Assergi, L’Aquila, Italy
² Department of Physics, Novosibirsk State University, Novosibirsk, 630090, Russia

^* e-mail: damian.ejlli@lngs.infn.it

Received: 3 April 2015
Accepted: 6 August 2015
Published online: 27 August 2015

Abstract

Axion production due to photon–axion mixing in tangled magnetic fields prior to the recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, the contribution of both processes to the CMB distortion in the case of resonant photon–axion mixing is studied. Assuming that the magnetic field power spectrum is approximated by a power law, with spectral index n, it is shown that for magnetic field cut-off scales 172.5 pc  pc, the axion contribution to the CMB distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using the COBE upper limit on and for the magnetic field scale  pc, a weaker limit in comparison with other studies on the magnetic field strength ( G) up to a factor 10 for the DFSZ axion model and axion mass  eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on is also presented.