The Cosmological Slingshot Scenario: A Stringy Early Times Universe

TL;DR

This paper proposes a string theory-inspired cosmological model where our universe is a brane in a warped space, avoiding initial singularity and matching observational data with a bouncing, non-singular early universe.

Contribution

It introduces a novel bouncing cosmology model based on brane dynamics in warped Calabi-Yau spaces, avoiding the big bang singularity and explaining density perturbations.

Findings

No initial singularity in the model.

Density perturbations have a slightly red spectral index.

Model aligns with WMAP observational data.

Abstract

A cosmological model for the early time Universe is proposed. In this model, the Universe is a wandering brane moving in a warped throat of a Calabi-Yau space. A non-zero angular momentum induces a turning point in the brane trajectory, and leads to a bouncing cosmology as experienced by an observer living on the brane. The Universe undergoes a decelerated contraction followed by an accelerating expansion and no big-bang singularity. Although the number of e-folds of accelerated motion is low (less than 2), standard cosmological problems are not present in our model thanks to the absence of an initial singularity and the violation of energy conditions of mirage matter at high energies. Density perturbations are also calculated in our model and we find a slightly red spectral index with negligible tensorial perturbations in compatibility with WMAP data.