Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations
We consider cosmic microwave background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do not detect isocurvature modes or large non-Gaussianity, it w...
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ftunivgeneve:oai:unige.ch:aou:unige:36504 2023-10-01T03:59:30+02:00 Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations Kinney, William H. Dizgah, Azadeh Moradinezhad Powell, Brian A. Riotto, Antonio Walter 2012 https://archive-ouverte.unige.ch/unige:36504 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevD.86.023527 https://archive-ouverte.unige.ch/unige:36504 unige:36504 info:eu-repo/semantics/openAccess ISSN: 1550-2368 Physical review. D. Particles, fields, gravitation, and cosmology, vol. 86, no. 2 (2012) info:eu-repo/classification/ddc/500.2 info:eu-repo/semantics/article Text Article scientifique info:eu-repo/semantics/publishedVersion 2012 ftunivgeneve https://doi.org/10.1103/PhysRevD.86.023527 2023-09-07T07:14:19Z We consider cosmic microwave background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do not detect isocurvature modes or large non-Gaussianity, it will not be possible to directly distinguish inflaton and curvaton contributions. We investigate whether current and future data can instead constrain the relative contributions of the two sources. We model the spectrum with a bimodal form consisting of a sum of two independent power laws, with different spectral indices. We quantify the ability of current and upcoming data sets to constrain the difference Δn in spectral indices, and relative fraction f of the subdominant power spectrum at a pivot scale of k0=0.017 Mpc−1 h. Data sets selected are the WMAP 7-year data, alone and in conjunction with South Pole Telescope data, and a synthetic data set comparable to the upcoming Planck data set. We find that current data show no increase in quality of fit for a mixed inflaton/curvaton power spectrum, and a pure power-law spectrum is favored. The ability to constrain independent parameters such as the tensor/scalar ratio is not substantially affected by the additional parameters in the fit. Planck will be capable of placing significant constraints on the parameter space for a bimodal spectrum. Article in Journal/Newspaper South pole Université de Genève: Archive ouverte UNIGE South Pole Pivot ENVELOPE(-30.239,-30.239,-80.667,-80.667) Physical Review D 86 2 |
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info:eu-repo/classification/ddc/500.2 Kinney, William H. Dizgah, Azadeh Moradinezhad Powell, Brian A. Riotto, Antonio Walter Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
topic_facet |
info:eu-repo/classification/ddc/500.2 |
description |
We consider cosmic microwave background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do not detect isocurvature modes or large non-Gaussianity, it will not be possible to directly distinguish inflaton and curvaton contributions. We investigate whether current and future data can instead constrain the relative contributions of the two sources. We model the spectrum with a bimodal form consisting of a sum of two independent power laws, with different spectral indices. We quantify the ability of current and upcoming data sets to constrain the difference Δn in spectral indices, and relative fraction f of the subdominant power spectrum at a pivot scale of k0=0.017 Mpc−1 h. Data sets selected are the WMAP 7-year data, alone and in conjunction with South Pole Telescope data, and a synthetic data set comparable to the upcoming Planck data set. We find that current data show no increase in quality of fit for a mixed inflaton/curvaton power spectrum, and a pure power-law spectrum is favored. The ability to constrain independent parameters such as the tensor/scalar ratio is not substantially affected by the additional parameters in the fit. Planck will be capable of placing significant constraints on the parameter space for a bimodal spectrum. |
format |
Article in Journal/Newspaper |
author |
Kinney, William H. Dizgah, Azadeh Moradinezhad Powell, Brian A. Riotto, Antonio Walter |
author_facet |
Kinney, William H. Dizgah, Azadeh Moradinezhad Powell, Brian A. Riotto, Antonio Walter |
author_sort |
Kinney, William H. |
title |
Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
title_short |
Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
title_full |
Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
title_fullStr |
Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
title_full_unstemmed |
Inflaton or curvaton? Constraints on bimodal primordial spectra from mixed perturbations |
title_sort |
inflaton or curvaton? constraints on bimodal primordial spectra from mixed perturbations |
publishDate |
2012 |
url |
https://archive-ouverte.unige.ch/unige:36504 |
long_lat |
ENVELOPE(-30.239,-30.239,-80.667,-80.667) |
geographic |
South Pole Pivot |
geographic_facet |
South Pole Pivot |
genre |
South pole |
genre_facet |
South pole |
op_source |
ISSN: 1550-2368 Physical review. D. Particles, fields, gravitation, and cosmology, vol. 86, no. 2 (2012) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevD.86.023527 https://archive-ouverte.unige.ch/unige:36504 unige:36504 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1103/PhysRevD.86.023527 |
container_title |
Physical Review D |
container_volume |
86 |
container_issue |
2 |
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1778533624171200512 |