Axion production and CMB spectral distortion in cosmological tangled magnetic field

作者：Ejlli Damian^*

来源：European Physical Journal C, 2015, 75(8): 397.

DOI：10.1140/epjc/s10052-015-3606-3

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 mu distortion in the case of resonant photon-axion mixing is studied. Assuming that the magnetic field power spectrum is approximated by a power law, P-B(k) alpha k(n) with spectral index n, it is shown that for magnetic field cut-off scales 172.5 pc <= lambda(B) <= 4 x 10(3) pc, the axion contribution to the CMB mu distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using the COBE upper limit on mu and for the magnetic field scale lambda(B) similar or equal to 415 pc, a weaker limit in comparison with other studies on the magnetic field strength (B-0 <= 8.5 x 10(-8) G) up to a factor 10 for the DFSZ axion model and axion mass m(a) >= 2.6 x 10(-6) eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on mu is also presented.

• 出版日期2015-8-27