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arXiv · hep-ph/0109214

Adiabatic CMB perturbations in pre-big bang string cosmology

Kari Enqvist·Martin S. Sloth
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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 $Δn$ in the range $-0.1 \lesssim Δn \lesssim 1$.

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Kari Enqvist, Martin S. Sloth. 2002-01-30. Adiabatic CMB perturbations in pre-big bang string cosmology. https://doi.org/10.1016/s0550-3213(02)00043-3

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