Single field inflation and non-Gaussianity

We study non-Gaussian signatures on the cosmic microwave background (CMB) radiation predicted within inflationary models with non-vacuum initial states for cosmological perturbations. The model incorporates a privileged scale, which implies the existence of a feature in the primordial power spectrum...

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Autor principal: Gangui, A.
Formato: JOUR
Materias:
anisotropy
article
correlation function
cosmos
microwave radiation
model
normal distribution
signal noise ratio
spectrum
temperature
vacuum
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_15507998_v66_n8_p_Gangui
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_15507998_v66_n8_p_Gangui
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spelling todo:paper_15507998_v66_n8_p_Gangui2023-10-03T16:23:50Z Single field inflation and non-Gaussianity Gangui, A. anisotropy article correlation function cosmos microwave radiation model normal distribution signal noise ratio spectrum temperature vacuum We study non-Gaussian signatures on the cosmic microwave background (CMB) radiation predicted within inflationary models with non-vacuum initial states for cosmological perturbations. The model incorporates a privileged scale, which implies the existence of a feature in the primordial power spectrum. This broken-scale-invariant model predicts a vanishing three-point correlation function for the CMB temperature anisotropies (or any other odd-numbered-point correlation function) whilst an intrinsic non-Gaussian signature arises for any even-numbered-point correlation function. We thus focus on the first non-vanishing moment, the CMB four-point function at zero lag, namely the kurtosis, and compute its expected value for different locations of the primordial feature in the spectrum, as suggested in the literature to conform with observations of large scale structure. The excess kurtosis is found to be negative and the signal to noise ratio for the dimensionless excess kurtosis parameter is equal to (Formula presented) almost independently of the free parameters of the model. This signature turns out to be undetectable. We conclude that, subject to current tests, Gaussianity is a generic property of single field inflationary models. The only uncertainty concerning this prediction is that the effect of back reaction has not yet been properly incorporated. The implications for the trans-Planckian problem of inflation are also briefly discussed. © 2002 The American Physical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_15507998_v66_n8_p_Gangui
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic anisotropy
article
correlation function
cosmos
microwave radiation
model
normal distribution
signal noise ratio
spectrum
temperature
vacuum
spellingShingle anisotropy
article
correlation function
cosmos
microwave radiation
model
normal distribution
signal noise ratio
spectrum
temperature
vacuum
Gangui, A.
Single field inflation and non-Gaussianity
topic_facet anisotropy
article
correlation function
cosmos
microwave radiation
model
normal distribution
signal noise ratio
spectrum
temperature
vacuum
description We study non-Gaussian signatures on the cosmic microwave background (CMB) radiation predicted within inflationary models with non-vacuum initial states for cosmological perturbations. The model incorporates a privileged scale, which implies the existence of a feature in the primordial power spectrum. This broken-scale-invariant model predicts a vanishing three-point correlation function for the CMB temperature anisotropies (or any other odd-numbered-point correlation function) whilst an intrinsic non-Gaussian signature arises for any even-numbered-point correlation function. We thus focus on the first non-vanishing moment, the CMB four-point function at zero lag, namely the kurtosis, and compute its expected value for different locations of the primordial feature in the spectrum, as suggested in the literature to conform with observations of large scale structure. The excess kurtosis is found to be negative and the signal to noise ratio for the dimensionless excess kurtosis parameter is equal to (Formula presented) almost independently of the free parameters of the model. This signature turns out to be undetectable. We conclude that, subject to current tests, Gaussianity is a generic property of single field inflationary models. The only uncertainty concerning this prediction is that the effect of back reaction has not yet been properly incorporated. The implications for the trans-Planckian problem of inflation are also briefly discussed. © 2002 The American Physical Society.
format JOUR
author Gangui, A.
author_facet Gangui, A.
author_sort Gangui, A.
title Single field inflation and non-Gaussianity
title_short Single field inflation and non-Gaussianity
title_full Single field inflation and non-Gaussianity
title_fullStr Single field inflation and non-Gaussianity
title_full_unstemmed Single field inflation and non-Gaussianity
title_sort single field inflation and non-gaussianity
url http://hdl.handle.net/20.500.12110/paper_15507998_v66_n8_p_Gangui
work_keys_str_mv AT ganguia singlefieldinflationandnongaussianity
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