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Cosmic Microwave Background Power Asymmetry from Non-Gaussian Modulation

Schmidt, Fabian and Hui, Lam (2013) Cosmic Microwave Background Power Asymmetry from Non-Gaussian Modulation. Physical Review Letters, 110 (1). Art. No. 011301 . ISSN 0031-9007.

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Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background power spectrum. This provides an alternative origin for a power asymmetry that is otherwise often ascribed to a breaking of statistical isotropy. The non-Gaussian modulation effect can be significant even for typical ∼10^(-5) perturbations while respecting current constraints on non-Gaussianity if the squeezed limit of the bispectrum is sufficiently infrared divergent. Just such a strongly infrared-divergent bispectrum has been claimed for inflation models with a non-Bunch-Davies initial state, for instance. Upper limits on the observed cosmic microwave background power asymmetry place stringent constraints on the duration of inflation in such models.

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Additional Information:© 2013 American Physical Society. Received 15 October 2012; published 2 January 2013; publisher error corrected 23 January 2013. We thank Raphael Flauger, Justin Khoury, Alberto Nicolis, and Albert Stebbins for useful discussions. F. S. was supported by the Moore Foundation at Caltech and the NASA Einstein Fellowship Program at Princeton. L. H. is supported by the DOE and NASA under Cooperative Agreements No. DE-FG02-92-ER40699 and No. NNX10AN14G.
Group:Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
NASA Einstein Fellowship ProgramUNSPECIFIED
Department of Energy (DOE)DE-FG02-92-ER40699
Issue or Number:1
Classification Code:PACS: 98.70.Vc, 98.65.Dx, 98.80.Cq, 98.80.Es
Record Number:CaltechAUTHORS:20130204-135345203
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:36765
Deposited By: Tony Diaz
Deposited On:08 Feb 2013 23:25
Last Modified:03 Oct 2019 04:41

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