2026-04-17T05:50:42Zhttps://recercat.cat/oai/requestoai:recercat.cat:2445/1317612025-12-05T16:11:46Zcom_2072_1057col_2072_478904col_2072_478917
RECERCAT
author
Mangilli, Anna
author
Verde, Licia
2019-04-08T11:02:21Z2019-04-08T11:02:21Z2009-12-082019-04-08T11:02:21Z
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.
(c) American Physical Society, 2009 info:eu-repo/semantics/openAccess
Física de partícules
Experiments
Ones de gravetat
Particle physics
Experiments
Gravity waves
Non-Gaussianity and the CMB bispectrum: Confusion between primordial and lensing-Rees-Sciama contribution?
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion