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A hemispherical power asymmetry from inflation

Erickcek, Adrienne L. and Kamionkowski, Marc and Carroll, Sean M. (2008) A hemispherical power asymmetry from inflation. Physical Review D, 78 (12). Art. No. 123520. ISSN 0556-2821.

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Measurements of cosmic microwave background temperature fluctuations by the Wilkinson Microwave Anisotropy Probe indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multifield inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a preinflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming cosmic microwave background experiments.

Item Type:Article
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Carroll, Sean M.0000-0002-4226-5758
Additional Information:© 2008 The American Physical Society. Received 3 June 2008; revised 10 July 2008; published 16 December 2008. We thank K. Górski and H. K. Eriksen for discussions. This work was supported by DOE Grant No. DE-FG03-92-ER40701 and the Gordon and Betty Moore Foundation.
Group:TAPIR, Moore Center for Theoretical Cosmology and Physics
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Department of EnergyDE-FG03-92-ER40701
Gordon and Betty Moore FoundationUNSPECIFIED
Record Number:CaltechAUTHORS:ERIprd08b
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12690
Deposited By: Archive Administrator
Deposited On:19 Dec 2008 23:46
Last Modified:17 Mar 2015 15:40

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