The Cosmological Slingshot Scenario: a Stringy Proposal for the Early Time Cosmology

TL;DR

This paper proposes a string theory-based cosmological model where our universe is a D3-brane moving in a warped throat, leading to a bouncing universe scenario that addresses key cosmological problems and matches observational data.

Contribution

It introduces the Cosmological Slingshot Scenario, a novel string-inspired model where brane dynamics produce a bouncing universe compatible with observations.

Findings

The model naturally avoids homogeneity, flatness, and isotropy problems.

Predicted primordial power spectrum aligns with WMAP data.

Demonstrates a string-theoretic realization of early universe cosmology.

Abstract

In the Cosmological Slingshot Scenario, our Universe is a D3-brane that extends in the 4d noncompact directions of a warped Calabi-Yau compactification of IIB Supergravity. Early time cosmology corresponds to a period in which the brane moves inside a warped throat where a non-vanishing angular momentum ensures that the trajectory of the brane has a turning point. The corresponding induced metric on the D3-brane experiences a cosmological evolution with a bounce. In this framework, the homogeneity, flatness, and isotropy problems of standard cosmology might be avoided. The power spectrum of primordial perturbations of the brane embedding can be found and it is shown to be in agreement to WMAP data.