Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2007-05-02
JCAP0707:002,2007
Physics
High Energy Physics
High Energy Physics - Theory
18 pages; V2: added references, version as published in JCAP
Scientific paper
10.1088/1475-7516/2007/07/002
An upper bound on the amplitude of the primordial gravitational wave spectrum generated during ultra-violet DBI inflation is derived. The bound is insensitive to the form of the inflaton potential and the warp factor of the compactified dimensions and can be expressed entirely in terms of observational parameters once the volume of the five-dimensional sub-manifold of the throat has been specified. For standard type IIB compactification schemes, the bound predicts undetectably small tensor perturbations with a tensor-scalar ratio $r < 10^{-7}$. This is incompatible with a corresponding lower limit of $r > 0.1 (1-n_s)$, which applies to any model that generates a red spectral index $n_s <1$ and a potentially detectable non-Gaussianity in the curvature perturbation. Possible ways of evading these bounds in more general DBI-type scenarios are discussed and a multiple-brane model is investigated as a specific example.
Huston Ian
Lidsey James E.
No associations
LandOfFree
Gravitational Wave Constraints on DBI Inflation 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 Gravitational Wave Constraints on DBI Inflation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational Wave Constraints on DBI Inflation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-674537