Antisymmetric-Tensor and Electromagnetic effects in an alpha'-non-perturbative Four-Dimensional String Cosmology
High Energy Physics - Theory
2008-11-26 v1 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
Abstract
Starting from an exact (in the Regge slope alpha') functional method for a bosonic stringy sigma-model, we investigate four-dimensional cosmological string solutions in graviton, dilaton and antisymmetric tensor backgrounds, compatible with world-sheet conformal invariance, and valid beyond perturbative expansions in powers of alpha'. The antisymmetric tensor field, playing the role of an axion in the four-dimensional target space time, leads to spatial anisotropies of the emergent Robertson-Walker expanding Universe, and, upon coupling the system to the electromagnetic field, it results in non-trivial optical activity. Some estimates of the corresponding effects are made and their relevance to current cosmology is briefly discussed.
Cite
@article{arxiv.0708.1154,
title = {Antisymmetric-Tensor and Electromagnetic effects in an alpha'-non-perturbative Four-Dimensional String Cosmology},
author = {Jean Alexandre and Nick E. Mavromatos and Dylan Tanner},
journal= {arXiv preprint arXiv:0708.1154},
year = {2008}
}