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Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity

We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty by 16% for WMAP and 5 % for Planck in the local case,...

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Detalles Bibliográficos
Autores principales: Liguori, M, Riotto, Antonio
Lenguaje:eng
Publicado: 2008
Materias:
Acceso en línea:https://dx.doi.org/10.1103/PhysRevD.78.123004
http://cds.cern.ch/record/1122086
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author Liguori, M
Riotto, Antonio
author_facet Liguori, M
Riotto, Antonio
author_sort Liguori, M
collection CERN
description We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty by 16% for WMAP and 5 % for Planck in the local case, whereas for equilateral configurations the correction term are 14% and 4%, respectively. If we assume for local f_NL a central value of order 60, according to recent WMAP 5-years estimates, we obtain for Planck a final correction \Delta f_NL = 3. Although not dramatic, this correction is at the level of the expected estimator uncertainty for Planck, and should then be taken into account when quoting the significance of an eventual future detection. In current estimates of f_NL the cosmological parameters are held fixed at their best-fit values. We finally note that the impact of uncertainties in the cosmological parameters on the final f_NL error bar would become totally negligible if the parameters were allowed to vary in the analysis and then marginalized over.
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institution Organización Europea para la Investigación Nuclear
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publishDate 2008
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spelling cern-11220862019-09-30T06:29:59Zdoi:10.1103/PhysRevD.78.123004http://cds.cern.ch/record/1122086engLiguori, MRiotto, AntonioImpact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-GaussianityAstrophysics and AstronomyWe study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty by 16% for WMAP and 5 % for Planck in the local case, whereas for equilateral configurations the correction term are 14% and 4%, respectively. If we assume for local f_NL a central value of order 60, according to recent WMAP 5-years estimates, we obtain for Planck a final correction \Delta f_NL = 3. Although not dramatic, this correction is at the level of the expected estimator uncertainty for Planck, and should then be taken into account when quoting the significance of an eventual future detection. In current estimates of f_NL the cosmological parameters are held fixed at their best-fit values. We finally note that the impact of uncertainties in the cosmological parameters on the final f_NL error bar would become totally negligible if the parameters were allowed to vary in the analysis and then marginalized over.arXiv:0808.3255oai:cds.cern.ch:11220862008-08-26
spellingShingle Astrophysics and Astronomy
Liguori, M
Riotto, Antonio
Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title_full Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title_fullStr Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title_full_unstemmed Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title_short Impact of Uncertainties in the Cosmological Parameters on the Measurement of Primordial non-Gaussianity
title_sort impact of uncertainties in the cosmological parameters on the measurement of primordial non-gaussianity
topic Astrophysics and Astronomy
url https://dx.doi.org/10.1103/PhysRevD.78.123004
http://cds.cern.ch/record/1122086
work_keys_str_mv AT liguorim impactofuncertaintiesinthecosmologicalparametersonthemeasurementofprimordialnongaussianity
AT riottoantonio impactofuncertaintiesinthecosmologicalparametersonthemeasurementofprimordialnongaussianity