Primordial Non-Gaussianity and Gravitational Waves: Observational Tests of Brane Inflation in String Theory

Lidsey, James E and Seery, David (2007) Primordial Non-Gaussianity and Gravitational Waves: Observational Tests of Brane Inflation in String Theory. Physical Review D, 75 (4). 043505. ISSN 1550-7998

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Abstract

We study brane inflation scenarios in a warped throat geometry and show that there exists a consistency condition between the non-Gaussianity of the curvature perturbation and the amplitude and scale-dependence of the primordial gravitational waves. This condition is independent of the warping of the throat and the form of the inflaton potential. We find that such a relation could be tested by a future CMB polarization experiment if the Planck satellite is able to detect both a gravitational wave background and a non-Gaussian statistic. In models where the observable stage of inflation occurs when the brane is in the tip region of the throat, we derive a further consistency condition involving the scalar spectral index, the tensor-scalar ratio and the curvature perturbation bispectrum. We show that when such a relation is combined with the WMAP3 results, it leads to a model-independent bound on the gravitational wave amplitude given by 0.001 < r < 0.01. This corresponds to the range of sensitivity of the next generation of CMB polarization experiments.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Depositing User: David Seery
Date Deposited: 06 Feb 2012 18:25
Last Modified: 13 Mar 2017 23:35
URI: http://sro.sussex.ac.uk/id/eprint/16181

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