Producing a Scale-Invariant Spectrum of Perturbations in a Hagedorn Phase of String Cosmology

Ali Nayeri,Cumrun Vafa,Robert H. Brandenberger

doi:10.1103/physrevlett.97.021302

Ali Nayeri, Cumrun Vafa + Show 1 more

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https://doi.org/10.1103/physrevlett.97.021302

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Journal: Physical Review Letters	Publication Date: Jul 14, 2006
Citations: 270	License type: cc-by

Affiliation: Harvard University, McGill University

Abstract

We study the generation of cosmological perturbations during the Hagedorn phase of string gas cosmology. Using tools of string thermodynamics we provide indications that it may be possible to obtain a nearly scale-invariant spectrum of cosmological fluctuations on scales which are of cosmological interest today. In our cosmological scenario, the early Hagedorn phase of string gas cosmology goes over smoothly into the radiation-dominated phase of standard cosmology, without having a period of cosmological inflation.

Highlights

Since superstring theory contains many scalar fields, it is not unreasonable to study the possibility that a period of cosmological inflation might naturally arise from string theory
We study the generation of cosmological perturbations during the Hagedorn phase of string gas cosmology
Most of the work on trying to obtain inflation from string theory, is done in the framework of a low energy effective field theory motivated by string theory, and does not take into account new symmetries and new degrees of freedom of string theory which are hard to see at the level of an effective field theory

Summary

Citable link Terms of Use

“Producing a Scale-Invariant Spectrum of Perturbations in a Hagedorn Phase of String Cosmology.”. Brandenberger2,† and Cumrun Vafa1‡ 1 Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138, USA 2 Department of Physics, McGill University, 3600 University Street, Montreal QC, H3A 2T8, Canada (Dated: April 23, 2018). We study the generation of cosmological perturbations during the Hagedorn phase of string gas cosmology. Using tools of string thermodynamics we provide indications that it may be possible to obtain a nearly scale-invariant spectrum of cosmological fluctuations on scales which are of cosmological interest today. The early Hagedorn phase of string gas cosmology goes over smoothly into the radiation-dominated phase of standard cosmology, without having a period of cosmological inflation

Introduction

Discussion and Conclusions