An Alternative to Inflation: The Cosmological Slingshot Scenario

by Dr Cristiano Germani (SISSA, Trieste)

Thursday 20 Mar 2008, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

I will introduce the Cosmological Slingshot Scenario, a stringy alternative to the standard early time cosmology. 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 the Slingshot 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 and a slightly red spectral index with negligible tensorial perturbations in compatibility with WMAP data can be easily obtained. I will conclude my talk by discussing the effective four dimensional theory of the Slingshot paradigm