The Cosmological Slingshot Scenario: Myths and Facts

TL;DR

This paper extends the Cosmological Slingshot Scenario to a brane in a Klebanov-Strassler throat, addressing key cosmological problems and demonstrating compatibility with observational data through detailed perturbation analysis.

Contribution

It generalizes the Slingshot model to a new geometric setting and provides a detailed analysis of perturbations, bouncing solutions, and frame transformations.

Findings

Horizon and isotropy problems are avoided.

Primordial power spectrum matches current observational data.

Bouncing solution maps to a monotonic scale factor in Einstein frame.

Abstract

We generalize the Cosmological Slingshot Scenario for a Slingshot brane moving in a Klebanov-Strassler throat. We show that the horizon and isotropy problems of standard cosmology are avoided, while the flatness problem is acceptably alleviated. Regarding the primordial perturbations, we identify their vacuum state and elucidate the evolution from the quantum to the classical regimes. Also, we calculate their exact power spectrum showing its compatibility with current data. We discuss the bouncing solution from a four dimensional point of view. In this framework the radial and angular motion of the Slingshot brane are described by two scalar fields. We show that the bouncing solution for the scale factor in String frame is mapped into a monotonically increasing (in conformal time) solution in the Einstein frame. We finally discuss about the regularity of the geometry in Einstein frame.