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Cosmological constraints on Lorentz violating dark energy

The role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the case for the cosmological constant problem. I...

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Autores principales: Audren, B., Blas, D., Lesgourgues, J., Sibiryakov, S.
Lenguaje:eng
Publicado: 2013
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1475-7516/2013/08/039
http://cds.cern.ch/record/1545054
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author Audren, B.
Blas, D.
Lesgourgues, J.
Sibiryakov, S.
author_facet Audren, B.
Blas, D.
Lesgourgues, J.
Sibiryakov, S.
author_sort Audren, B.
collection CERN
description The role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the case for the cosmological constant problem. Indeed, it has been shown that breaking Lorentz invariance provides Lagrangians that can drive the current acceleration of the universe without experiencing large corrections from ultraviolet physics. In this work, we focus on the simplest model of this type, called ThetaCDM, and study its cosmological implications in detail. At the background level, this model cannot be distinguished from LambdaCDM. The differences appear at the level of perturbations. We show that in ThetaCDM, the spectrum of CMB anisotropies and matter fluctuations may be affected by a rescaling of the gravitational constant in the Poisson equation, by the presence of extra contributions to the anisotropic stress, and finally by the existence of extra clustering degrees of freedom. To explore these modifications accurately, we modify the Boltzmann code CLASS. We then use the parameter inference code Monte Python to confront ThetaCDM with data from WMAP-7, SPT and WiggleZ. We obtain strong bounds on the parameters accounting for deviations from LambdaCDM. In particular, we find that the discrepancy between the gravitational constants appearing in the Poisson and Friedmann equations is constrained at the level 1.8%.
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institution Organización Europea para la Investigación Nuclear
language eng
publishDate 2013
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spelling cern-15450542023-01-26T07:20:02Zdoi:10.1088/1475-7516/2013/08/039http://cds.cern.ch/record/1545054engAudren, B.Blas, D.Lesgourgues, J.Sibiryakov, S.Cosmological constraints on Lorentz violating dark energyAstrophysics and AstronomyThe role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the case for the cosmological constant problem. Indeed, it has been shown that breaking Lorentz invariance provides Lagrangians that can drive the current acceleration of the universe without experiencing large corrections from ultraviolet physics. In this work, we focus on the simplest model of this type, called ThetaCDM, and study its cosmological implications in detail. At the background level, this model cannot be distinguished from LambdaCDM. The differences appear at the level of perturbations. We show that in ThetaCDM, the spectrum of CMB anisotropies and matter fluctuations may be affected by a rescaling of the gravitational constant in the Poisson equation, by the presence of extra contributions to the anisotropic stress, and finally by the existence of extra clustering degrees of freedom. To explore these modifications accurately, we modify the Boltzmann code CLASS. We then use the parameter inference code Monte Python to confront ThetaCDM with data from WMAP-7, SPT and WiggleZ. We obtain strong bounds on the parameters accounting for deviations from LambdaCDM. In particular, we find that the discrepancy between the gravitational constants appearing in the Poisson and Friedmann equations is constrained at the level 1.8%.The role of Lorentz invariance as a fundamental symmetry of nature hasbeen lately reconsidered in different approaches to quantum gravity.It is thus natural to study whether other puzzles of physics may besolved within these proposals. This may be the case for thecosmological constant problem. Indeed, it has been shown that breakingLorentz invariance provides Lagrangians that can drive the currentacceleration of the universe without experiencing large correctionsfrom ultraviolet physics. In this work, we focus on the simplestmodel of this type, called ΘCDM, and study its cosmologicalimplications in detail. At the background level, this model cannot bedistinguished from ΛCDM. The differences appear at the levelof perturbations. We show that in ΘCDM, the spectrum of CMBanisotropies and matter fluctuations may be affected by a rescaling ofthe gravitational constant in the Poisson equation, by the presence ofextra contributions to the anisotropic stress, and finally by theexistence of extra clustering degrees of freedom. To explore thesemodifications accurately, we modify the Boltzmann code class.We then use the parameter inference code Monte Python toconfront ΘCDM with data from WMAP-7, SPT and WiggleZ. We obtainstrong bounds on the parameters accounting for deviations fromΛCDM. In particular, we find that the discrepancy between thegravitational constants appearing in the Poisson and Friedmannequations is constrained at the level of 1.8%.The role of Lorentz invariance as a fundamental symmetry of nature has been lately reconsidered in different approaches to quantum gravity. It is thus natural to study whether other puzzles of physics may be solved within these proposals. This may be the case for the cosmological constant problem. Indeed, it has been shown that breaking Lorentz invariance provides Lagrangians that can drive the current acceleration of the universe without experiencing large corrections from ultraviolet physics. In this work, we focus on the simplest model of this type, called ThetaCDM, and study its cosmological implications in detail. At the background level, this model cannot be distinguished from LambdaCDM. The differences appear at the level of perturbations. We show that in ThetaCDM, the spectrum of CMB anisotropies and matter fluctuations may be affected by a rescaling of the gravitational constant in the Poisson equation, by the presence of extra contributions to the anisotropic stress, and finally by the existence of extra clustering degrees of freedom. To explore these modifications accurately, we modify the Boltzmann code CLASS. We then use the parameter inference code Monte Python to confront ThetaCDM with data from WMAP-7, SPT and WiggleZ. We obtain strong bounds on the parameters accounting for deviations from LambdaCDM. In particular, we find that the discrepancy between the gravitational constants appearing in the Poisson and Friedmann equations is constrained at the level 1.8%.arXiv:1305.0009CERN-PH-TH-2013-085LAPTH-022-13CERN-PH-TH-2013-085LAPTH-022-13oai:cds.cern.ch:15450542013-05-02
spellingShingle Astrophysics and Astronomy
Audren, B.
Blas, D.
Lesgourgues, J.
Sibiryakov, S.
Cosmological constraints on Lorentz violating dark energy
title Cosmological constraints on Lorentz violating dark energy
title_full Cosmological constraints on Lorentz violating dark energy
title_fullStr Cosmological constraints on Lorentz violating dark energy
title_full_unstemmed Cosmological constraints on Lorentz violating dark energy
title_short Cosmological constraints on Lorentz violating dark energy
title_sort cosmological constraints on lorentz violating dark energy
topic Astrophysics and Astronomy
url https://dx.doi.org/10.1088/1475-7516/2013/08/039
http://cds.cern.ch/record/1545054
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AT blasd cosmologicalconstraintsonlorentzviolatingdarkenergy
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AT sibiryakovs cosmologicalconstraintsonlorentzviolatingdarkenergy