Stealth magnetic field in de Sitter spacetime
Abstract
In the context of a U(1) gauge theory non-minimally coupled to scalar-tensor gravity, we find a cosmological attractor solution that represents a de Sitter universe with a homogeneous magnetic field. The solution fully takes into account backreaction of the magnetic field to the geometry and the scalar field. Such a solution is made possible by scaling-type global symmetry and fine-tuning of two parameters of the theory. If the fine-tuning is relaxed then the solution is deformed to an axisymmetric Bianchi type-I universe with constant curvature invariants, a homogeneous magnetic field and a homogeneous electric field. Implications to inflationary magnetogenesis are briefly discussed.
Cite
@article{arxiv.1607.07041,
title = {Stealth magnetic field in de Sitter spacetime},
author = {Shinji Mukohyama},
journal= {arXiv preprint arXiv:1607.07041},
year = {2017}
}
Comments
10 pages; expanded discussion about implications to inflationary magnetogenesis, including the amplitude today, observational constraint, statistical anisotropy, etc (v2); version accepted for publication as a Rapid Communication in Physical Review D (v3)