Generic estimates for magnetic fields generated during inflation including Dirac-Born-Infeld theories
Abstract
We estimate the strength of large-scale magnetic fields produced during inflation in the framework of Dirac-Born-Infeld (DBI) theories. This analysis is sufficiently general in the sense that it covers most of conformal symmetry breaking theories in which the electromagnetic field is coupled to a scalar field. In DBI theories there is an additional factor associated with the speed of sound, which allows a possibility to lead to an extra amplification of the magnetic field in a ultra-relativistic region. We clarify the conditions under which seed magnetic fields to feed the galactic dynamo mechanism at a decoupling epoch as well as present magnetic fields on galactic scales are sufficiently generated to satisfy observational bounds.
Cite
@article{arxiv.0805.3862,
title = {Generic estimates for magnetic fields generated during inflation including Dirac-Born-Infeld theories},
author = {Kazuharu Bamba and Nobuyoshi Ohta and Shinji Tsujikawa},
journal= {arXiv preprint arXiv:0805.3862},
year = {2010}
}
Comments
7 pages, no figure, accepted in Phys. Rev. D