A Stringy Alternative to Inflation: The Cosmological Slingshot Scenario.

CRISTIANO GERMANI, NICOLAS GRANDI, ALEX KEHAGIAS

CLASSICAL AND QUANTUM GRAVITY

Institute of Physics and IOP Publishing Limited 2008.

Lugar: London; Año: 2008 vol. 25 p. 1 - 32

0264-9381

 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.