Adiabatic CMB perturbations in pre-big bang string cosmology
High Energy Physics - Phenomenology
2009-11-07 v3 Astrophysics
High Energy Physics - Theory
Abstract
We consider the pre-big bang scenario with a massive axion field which starts to dominate energy density when oscillating in an instanton-induced potential and subsequently reheats the universe as it decays into photons, thus creating adiabatic CMB perturbations. We find that the fluctuations in the axion field can give rise to a nearly flat spectrum of adiabatic perturbations with a spectral tilt in the range .
Cite
@article{arxiv.hep-ph/0109214,
title = {Adiabatic CMB perturbations in pre-big bang string cosmology},
author = {Kari Enqvist and Martin S. Sloth},
journal= {arXiv preprint arXiv:hep-ph/0109214},
year = {2009}
}
Comments
15 pages, 1 figure; Version to appear in Nucl.Phys.B. Figure improved, discussion and one reference added