Primordial nonGaussianity and gravitational waves: Observational tests of brane inflation in string theory
Abstract
We study brane inflation scenarios in a warped throat geometry and show that there exists a consistency condition between the nonGaussianity of the curvature perturbation and the amplitude and scaledependence 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 nonGaussian 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 tensorscalar ratio and the curvature perturbation bispectrum. We show that when such a relation is combined with the WMAP3 results, it leads to a modelindependent bound on the gravitational wave amplitude given by 10{sup 3}<r<10{sup 2}. This corresponds to the range of sensitivity of the next generation of CMB polarization experiments.
 Authors:

 Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS (United Kingdom)
 Publication Date:
 OSTI Identifier:
 21011048
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. D, Particles Fields
 Additional Journal Information:
 Journal Volume: 75; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevD.75.043505; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 05562821
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AMPLITUDES; BRANES; COSMIC RADIATION; COSMOLOGY; DISTURBANCES; GRAVITATION; GRAVITATIONAL WAVES; POLARIZATION; POTENTIALS; RELICT RADIATION; SENSITIVITY; STRING MODELS; TENSORS
Citation Formats
Lidsey, James E, and Seery, David. Primordial nonGaussianity and gravitational waves: Observational tests of brane inflation in string theory. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.043505.
Lidsey, James E, & Seery, David. Primordial nonGaussianity and gravitational waves: Observational tests of brane inflation in string theory. United States. doi:10.1103/PHYSREVD.75.043505.
Lidsey, James E, and Seery, David. Thu .
"Primordial nonGaussianity and gravitational waves: Observational tests of brane inflation in string theory". United States. doi:10.1103/PHYSREVD.75.043505.
@article{osti_21011048,
title = {Primordial nonGaussianity and gravitational waves: Observational tests of brane inflation in string theory},
author = {Lidsey, James E and Seery, David},
abstractNote = {We study brane inflation scenarios in a warped throat geometry and show that there exists a consistency condition between the nonGaussianity of the curvature perturbation and the amplitude and scaledependence 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 nonGaussian 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 tensorscalar ratio and the curvature perturbation bispectrum. We show that when such a relation is combined with the WMAP3 results, it leads to a modelindependent bound on the gravitational wave amplitude given by 10{sup 3}<r<10{sup 2}. This corresponds to the range of sensitivity of the next generation of CMB polarization experiments.},
doi = {10.1103/PHYSREVD.75.043505},
journal = {Physical Review. D, Particles Fields},
issn = {05562821},
number = 4,
volume = 75,
place = {United States},
year = {2007},
month = {2}
}