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Structure formation with massive neutrinos: going beyond linear theory

We compute non-linear corrections to the matter power spectrum taking the time- and scale-dependent free-streaming length of neutrinos into account. We adopt a hybrid scheme that matches the full Boltzmann hierarchy to an effective two-fluid description at an intermediate redshift. The non-lineariti...

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Detalles Bibliográficos
Autores principales: Blas, Diego, Garny, Mathias, Konstandin, Thomas, Lesgourgues, Julien
Lenguaje:eng
Publicado: 2014
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1475-7516/2014/11/039
http://cds.cern.ch/record/1750009
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author Blas, Diego
Garny, Mathias
Konstandin, Thomas
Lesgourgues, Julien
author_facet Blas, Diego
Garny, Mathias
Konstandin, Thomas
Lesgourgues, Julien
author_sort Blas, Diego
collection CERN
description We compute non-linear corrections to the matter power spectrum taking the time- and scale-dependent free-streaming length of neutrinos into account. We adopt a hybrid scheme that matches the full Boltzmann hierarchy to an effective two-fluid description at an intermediate redshift. The non-linearities in the neutrino component are taken into account by using an extension of the time-flow framework. We point out that this remedies a spurious behaviour that occurs when neglecting non-linear terms for neutrinos. This behaviour is related to how efficiently short modes decouple from long modes and can be traced back to the violation of momentum conservation if neutrinos are treated linearly. Furthermore, we compare our results at next to leading order to various other methods and quantify the accuracy of the fluid description. Due to the correct decoupling behaviour of short modes, the two-fluid scheme is a suitable starting point to compute higher orders in perturbations or for resummation methods.
id cern-1750009
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2014
record_format invenio
spelling cern-17500092023-01-26T08:06:54Zdoi:10.1088/1475-7516/2014/11/039http://cds.cern.ch/record/1750009engBlas, DiegoGarny, MathiasKonstandin, ThomasLesgourgues, JulienStructure formation with massive neutrinos: going beyond linear theoryAstrophysics and AstronomyWe compute non-linear corrections to the matter power spectrum taking the time- and scale-dependent free-streaming length of neutrinos into account. We adopt a hybrid scheme that matches the full Boltzmann hierarchy to an effective two-fluid description at an intermediate redshift. The non-linearities in the neutrino component are taken into account by using an extension of the time-flow framework. We point out that this remedies a spurious behaviour that occurs when neglecting non-linear terms for neutrinos. This behaviour is related to how efficiently short modes decouple from long modes and can be traced back to the violation of momentum conservation if neutrinos are treated linearly. Furthermore, we compare our results at next to leading order to various other methods and quantify the accuracy of the fluid description. Due to the correct decoupling behaviour of short modes, the two-fluid scheme is a suitable starting point to compute higher orders in perturbations or for resummation methods.We compute non-linear corrections to the matter power spectrum taking the time- and scale-dependent free-streaming length of neutrinos into account. We adopt a hybrid scheme that matches the full Boltzmann hierarchy to an effective two-fluid description at an intermediate redshift. The non-linearities in the neutrino component are taken into account by using an extension of the time-flow framework. We point out that this remedies a spurious behaviour that occurs when neglecting non-linear terms for neutrinos. This behaviour is related to how efficiently short modes decouple from long modes and can be traced back to the violation of momentum conservation if neutrinos are treated linearly. Furthermore, we compare our results at next to leading order to various other methods and quantify the accuracy of the fluid description. Due to the correct decoupling behaviour of short modes, the two-fluid scheme is a suitable starting point to compute higher orders in perturbations or for resummation methods.We compute non-linear corrections to the matter power spectrum taking the time- and scale-dependent free-streaming length of neutrinos into account. We adopt a hybrid scheme that matches the full Boltzmann hierarchy to an effective two-fluid description at an intermediate redshift. The non-linearities in the neutrino component are taken into account by using an extension of the time-flow framework. We point out that this remedies a spurious behaviour that occurs when neglecting non-linear terms for neutrinos. This behaviour is related to how efficiently short modes decouple from long modes and can be traced back to the violation of momentum conservation if neutrinos are treated linearly. Furthermore, we compare our results at next to leading order to various other methods and quantify the accuracy of the fluid description. Due to the correct decoupling behaviour of short modes, the two-fluid scheme is a suitable starting point to compute higher orders in perturbations or for resummation methods.arXiv:1408.2995CERN-PH-TH-2014-149DESY-14-143CERN-PH-TH-2014-149DESY 14-143oai:cds.cern.ch:17500092014-08-13
spellingShingle Astrophysics and Astronomy
Blas, Diego
Garny, Mathias
Konstandin, Thomas
Lesgourgues, Julien
Structure formation with massive neutrinos: going beyond linear theory
title Structure formation with massive neutrinos: going beyond linear theory
title_full Structure formation with massive neutrinos: going beyond linear theory
title_fullStr Structure formation with massive neutrinos: going beyond linear theory
title_full_unstemmed Structure formation with massive neutrinos: going beyond linear theory
title_short Structure formation with massive neutrinos: going beyond linear theory
title_sort structure formation with massive neutrinos: going beyond linear theory
topic Astrophysics and Astronomy
url https://dx.doi.org/10.1088/1475-7516/2014/11/039
http://cds.cern.ch/record/1750009
work_keys_str_mv AT blasdiego structureformationwithmassiveneutrinosgoingbeyondlineartheory
AT garnymathias structureformationwithmassiveneutrinosgoingbeyondlineartheory
AT konstandinthomas structureformationwithmassiveneutrinosgoingbeyondlineartheory
AT lesgourguesjulien structureformationwithmassiveneutrinosgoingbeyondlineartheory