Running of the Spectrum of Cosmological Perturbations in String Gas Cosmology

Abstract

We compute the running of the spectrum of cosmological perturbations in String Gas Cosmology, making use of a smooth parametrization of the transition between the early Hagedorn phase and the later radiation phase. We find that the running has the same sign as in simple models of single scalar field inflation. Its magnitude is proportional to $(1-n_s)$ ($n_s$ being the slope index of the spectrum), and it is thus parametrically larger than for inflationary cosmology, where it is proportional to $(1-n_s{)}^2$.

6 pages, 3 figures

References in corpus (6)

• G-inflation: inflation driven by the Galileon field
• Tensor Modes from a Primordial Hagedorn Phase of String Cosmology
• String Gas Cosmology and Structure Formation
• Closed String Thermodynamics and a Blue Tensor Spectrum
• Inflation Free, Stringy Generation of Scale-Invariant Cosmological Fluctuations in D = 3 + 1 Dimensions
• Differentiating G-inflation from String Gas Cosmology using the Effective Field Theory Approach

Cited by in corpus (4)

• T-Dual Cosmological Solutions of Double Field Theory II
• de Sitter Swampland Conjecture in String Field Inflation
• Inflation in String Field Theory
• String length constraining from the stochastic gravitational waves background