Cosmological Structure Problem of the Pre-Big Bang Scenario

Abstract

We calculate the density and gravitational wave spectrums generated in a version of string cosmology termed pre-big bang scenario. The large scale structures are originated from quantum fluctuations of the metric and dilaton field during a pole-like inflation stage driven by a potential-less dilaton field realized in the low-energy effective action of string theory. The generated classical density field and the gravitational wave in the second horizon crossing epoch show tilted spectrums with n ~ 4 and n_T ~ 3, respectively. These differ from the observed spectrum of the large angular scale anisotropy of the cosmic microwave background radiation which supports scale invariant ones with n ~ 1 and n_T ~ 0. This suggests that the pre-big bang stage is not suitable for generating the present day observable large scale structures, and suggests the importance of investigating the quantum generation processes during stringy era with higher order quantum correction terms.

10 pages, thoroughly revised, title changed, Astroparticle Physics

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Cited by in corpus (14)

• The Pre-Big Bang Scenario in String Cosmology
• Superstring Cosmology
• Evolution of cosmological perturbations in non-singular string cosmologies
• Cosmological structure problem of the ekpyrotic scenario
• Inflationary spectra in generalized gravity: Unified forms
• Conserved cosmological structures in the one-loop superstring effective action
• String theoretic axion coupling and the evolution of cosmic structures
• Gravitational Wave Spectrums from Pole-like Inflations based on Generalized Gravity Theories
• COBE constraints on inflation models with a massive non-minimal scalar field
• Identification of perturbation modes and controversies in ekpyrotic perturbations
• Axion perturbation spectra in string cosmologies
• Cosmologies from higher-order string corrections
• Modular Quantum Cosmology
• Evolution of linear perturbations through a bouncing world model: Is the near Harrison-Zel'dovich spectrum possible via a bounce?