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arXiv · 0805.3862

Generic estimates for magnetic fields generated during inflation including Dirac-Born-Infeld theories

Kazuharu Bamba·Nobuyoshi Ohta·Shinji Tsujikawa
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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.

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Kazuharu Bamba, Nobuyoshi Ohta, Shinji Tsujikawa. 2008-07-25. Generic estimates for magnetic fields generated during inflation including Dirac-Born-Infeld theories. https://doi.org/10.1103/physrevd.78.043524

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