A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio

Details A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio

2007-09-17

arxiv.org/abs/0709.2671v3

Mod.Phys.Lett.A23:727-735,2008

Astronomy and Astrophysics

Astrophysics

5 pages, version 3, minor changes from version 2

Scientific paper

10.1142/S0217732308026777

There are large classes of inflationary models, particularly popular in the context of string theory and brane world approaches to inflation, in which the ratio of linearized tensor to scalar metric fluctuations is very small. In such models, however, gravitational waves produced by scalar modes cannot be neglected. We derive the lower bound on the tensor-to-scalar ratio by considering the back-reaction of the scalar perturbations as a source of gravitational waves. These results show that no cosmological model that is compatible with a metric scalar amplitude of $\approx 10^{-5}$ can have a ratio of the tensor to scalar power spectra less than $\approx 10^{-8}$ at recombination and that higher-order terms leads to logarithmic growth for r during radiation domination. Our lower bound also applies to non-inflationary models which produce an almost scale-invariant spectrum of coherent super-Hubble scale metric fluctuations.

Affiliated with

Also associated with

No associations

Rating

A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Back-reaction Induced Lower Bound on the Tensor-to-Scalar Ratio will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-379091