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http://hdl.handle.net/2445/131761
Title: | Non-Gaussianity and the CMB bispectrum: Confusion between primordial and lensing-Rees-Sciama contribution? |
Author: | Mangilli, Anna Verde, Licia |
Keywords: | Física de partícules Experiments Ones de gravetat Particle physics Experiments Gravity waves |
Issue Date: | 8-Dec-2009 |
Publisher: | American Physical Society |
Abstract: | We revisit the predictions for the expected cosmic microwave background bispectrum signal from the cross-correlation of the primary-lensing-Rees-Sciama signal; we point out that it can be a significant contaminant to the bispectrum signal from primordial non-Gaussianity of the local type. This non-Gaussianity, usually parametrized by the non-Gaussian parameter f N L , arises, for example, in multifield inflation. In particular both signals are frequency-independent, and are maximized for nearly squeezed configurations. While their detailed scale-dependence and harmonic imprints are different for generic bispectrum shapes, we show that, if not included in the modeling, the primary-lensing-Rees-Sciama contribution yields an effective f N L of 10 when using a bispectrum estimator optimized for local non-Gaussianity. Considering that expected 1 − σ errors on f N L are < 10 from forthcoming experiments, we conclude that the contribution from this signal must be included in future constraints on f N L from the cosmic microwave background bispectrum. |
Note: | Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.80.123007 |
It is part of: | Physical Review D, 2009, vol. 80, num. 12, p. 123007 |
URI: | http://hdl.handle.net/2445/131761 |
Related resource: | https://doi.org/10.1103/PhysRevD.80.123007 |
ISSN: | 1550-7998 |
Appears in Collections: | Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB)) Publicacions de projectes de recerca finançats per la UE |
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