http://arxiv.org/abs/2001.00194
We compute the 21-cm differential brightness temperature of the intergalactic medium in presence of primordial helical magnetic field for redshift $z=30-10$. It is shown that the gas temperature can be lowered to 3.2 degree Kelvin at $z=17$ by the alpha-effect due to the twisting of magnetic field lines by eddies generated due to the turbulence generated at earlier times. Using the EDGES results, we find the upper and lower limits on the primordial magnetic field $6\times 10^{-3}~{\rm nG} $ & $5\times 10^{-4}~{\rm nG}$ respectively. We also discuss the effect of Ly$\alpha$ background on the bounds. Our results do not require any new physics in terms of dark-matter.
P. Natwariya and J. Bhatt
Fri, 3 Jan 20
38/45
Comments: 4 pages, 4 figures
You must be logged in to post a comment.