Generation of magnetic field from cosmological perturbations
Abstract
We discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the second order. The collision term is shown to induce electric current, which then generate magnetic field. There are three contributions, two of which can be evaluated from the first-order quantities, while the other one is fluid vorticity which is purely second order. We compute numerically the magnitudes of the former contributions and shows that the amplitude of the produced magnetic field is about at 10kpc comoving scale at present. Compared to astrophysical and inflationary mechanisms for seed-field generation, our study suffers from much less ambiguities concerning unknown physics and/or processes.
Keywords
Cite
@article{arxiv.astro-ph/0601243,
title = {Generation of magnetic field from cosmological perturbations},
author = {Keitaro Takahashi and Kiyotomo Ichiki and Hiroshi Ohno and Hidekazu Hanayama and Naoshi Sugiyama},
journal= {arXiv preprint arXiv:astro-ph/0601243},
year = {2007}
}
Comments
4pages, 2figures, to appear in the Proc. of the Int. Conference on "The Origin and Evolution of Cosmic Magnetism", Bologna, 29 August - 2 September 2005, eds. R. Beck, G. Brunetti, L. Feretti and B. Gaensler (Atronomische Nachrichten, Wiley, 2005)