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Inflationary gravitational-wave background and measurements of the scalar spectral index

Smith, Tristan L. and Kamionkowski, Marc and Cooray, Asantha (2008) Inflationary gravitational-wave background and measurements of the scalar spectral index. Physical Review D, 78 (8). Art. No. 083525. ISSN 2470-0010. doi:10.1103/PhysRevD.78.083525.

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Inflation predicts a stochastic background of gravitational waves over a broad range of frequencies, from those accessible with cosmic microwave background (CMB) measurements, to those accessible directly with gravitational-wave detectors, like NASA's Big-Bang Observer (BBO), currently under study. In a previous paper [Phys. Rev. D 73, 023504 (2006)] we connected CMB constraints to the amplitude and tensor spectral tilt of the inflationary gravitational-wave background (IGWB) at BBO frequencies for four classes of models of inflation by directly solving the inflationary equations of motion. Here we extend that analysis by including results obtained in the Wilkinson Microwave Anisotropy Probe third-year data release as well as by considering two additional classes of inflationary models. As often noted in the literature, the recent indication that the primordial density power spectrum has a red spectral index implies (with some caveats) that the amplitude of the IGWB may be large enough to be observable in the CMB polarization. Here we also explore the implications for the direct detection of the IGWB.

Item Type:Article
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URLURL TypeDescription
Kamionkowski, Marc0000-0001-7018-2055
Cooray, Asantha0000-0002-3892-0190
Additional Information:© 2008 The American Physical Society. (Received 13 February 2008; published 16 October 2008) We thank W. Kinney, D. Baumann, and D. Grin for useful discussions. We thank E.S. Phinney and A.A. Starobinsky for pointing out the erroneous factor of 4 in our previous expression for the gravitational-wave transfer function. This work was supported at Caltech by DOE Grant No. DE-FG03-92-ER40701, NASA Grant No. NNG05GF69G, and the Gordon and Betty Moore Foundation, and at UC Irvine by NSF CAREER No. AST-0645427.
Group:TAPIR, Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Department of Energy (DOE)DE-FG03-92-ER40701
Gordon and Betty Moore FoundationUNSPECIFIED
Issue or Number:8
Record Number:CaltechAUTHORS:SMIprd08b
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12011
Deposited By: Archive Administrator
Deposited On:18 Oct 2008 04:21
Last Modified:08 Nov 2021 22:23

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