Model-independent reconstruction of the expansion history of the Universe and the properties of dark energy

Shafieloo, Arman

doi:10.1111/j.1365-2966.2007.12175.x

Cited by 107 publications

(158 citation statements)

References 67 publications

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“…The Eisenstein et al (2005) BAO peak measurement has been used in conjunction with other data to place constraints on various cosmological models (see, e.g., Alam & Sahni 2006;Nesseris & Perivolaropulos 2007;Movahed et al 2009;Zhang & Wu 2007;Wright 2007;Shafieloo 2007). The more recent Percival et al (2007a) data have also been used for this purpose (Ishida et al 2008;Lazkoz et al 2008).…”

Section: Resultsmentioning

confidence: 99%

Constraints on Dark Energy From Baryon Acoustic Peak and Galaxy Cluster Gas Mass Measurements

Samushia

Ratra

2009

ApJ

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We use baryon acoustic peak measurements by Eisenstein et al. and Percival et al., together with the Wilkinson Microwave Anisotropy Probe (WMAP) measurement of the apparent acoustic horizon angle, and galaxy cluster gas mass fraction measurements of Allen et al., to constrain a slowly rolling scalar field dark energy model, φCDM, in which dark energy's energy density changes in time. We also compare our φCDM results with those derived for two more common dark energy models: the time-independent cosmological constant model, ΛCDM, and the XCDM parameterization of dark energy's equation of state. For time-independent dark energy, the Percival et al. measurements effectively constrain spatial curvature and favor a close to the spatially flat model, mostly due to the WMAP cosmic microwave background prior used in the analysis. In a spatially flat model the Percival et al. data less effectively constrain time-varying dark energy. The joint baryon acoustic peak and galaxy cluster gas mass constraints on the φCDM model are consistent with but tighter than those derived from other data. A timeindependent cosmological constant in a spatially flat model provides a good fit to the joint data, while the α parameter in the inverse power-law potential φCDM model is constrained to be less than about 4 at 3σ confidence level.

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Section: Resultsmentioning

confidence: 99%

Constraints on Dark Energy From Baryon Acoustic Peak and Galaxy Cluster Gas Mass Measurements

Samushia

Ratra

2009

ApJ

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“…While there are several methods such as principle component analysis [19][20][21], Gaussian smoothing [22,23] and Gaussian processes [24][25][26][27], in this paper we will reconstruct D(z) and its derivatives more precisely by using the GP method.…”

Section: Reconstruction Methodsmentioning

confidence: 99%

Reconstructing the interaction between dark energy and dark matter using Gaussian processes

2015

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We present a nonparametric approach to reconstruct the interaction between dark energy and dark matter directly from SNIa Union 2.1 data using Gaussian processes, which is a fully Bayesian approach for smoothing data. In this method, once the equation of state (w) of dark energy is specified, the interaction can be reconstructed as a function of redshift. For the decaying vacuum energy case with w = −1, the reconstructed interaction is consistent with the standard ΛCDM model, namely, there is no evidence for the interaction. This also holds for the constant w cases from −0.9 to −1.1 and for the Chevallier-Polarski-Linder (CPL) parametrization case. If the equation of state deviates obviously from −1, the reconstructed interaction exists at 95% confidence level. This shows the degeneracy between the interaction and the equation of state of dark energy when they get constraints from the observational data.PACS numbers: 95.36.+x, 98.80.Es

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“…the Hubble parameter h(z)) have been carried out before [24,25], from which the equation of state can also be reconstructed. Also note that certain parametrization of the dark energy equation of state may 'artificially' limit the properties of dark energy from explaining a few effects, such as the recent slowdown of cosmic acceleration [26].…”

Section: Introductionmentioning

confidence: 99%

Post-Planck dark energy constraints

et al. 2015

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Abstract. We constrain plausible dark energy models, parametrized by multiple candidate equation of state, using the recently published Cosmic Microwave Background (CMB) temperature anisotropy data from Planck together with the WMAP-9 low-ℓ polarization data and data from low redshift surveys. To circumvent the limitations of any particular equation of state towards describing all existing dark energy models, we work with three different equation of state covering a broader class of dark energy models and, hence, provide more robust and generic constraints on the dark energy properties. We show that a clear tension exists between dark energy constraints from CMB and non-CMB observations when one allows for dark energy models having both phantom and non-phantom behavior; while CMB is more favorable to phantom models, the low-z data prefers model with behavior close to a Cosmological Constant. Further, we reconstruct the equation of state of dark energy as a function of redshift using the results from combined CMB and non-CMB data and find that Cosmological Constant lies outside the 1σ band for multiple dark energy models allowing phantom behavior. A considerable fine tuning is needed to keep models with strict non-phantom history inside 2σ allowed range. This result might motivate one to construct phantom models of dark energy, which is achievable in the presence of higher derivative operators as in string theory. However, disallowing phantom behavior, based only on strong theoretical prior, leads to both CMB and non-CMB datasets agree on the nature of dark energy, with the mean equation of state being very close to the Cosmological Constant. Finally, to illustrate the impact of additional dark energy parameters on other cosmological parameters, we provide the cosmological parameter constraints for the "Standard Model of Cosmology" including an evolving dark energy component, for the different dark energy models.

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Model-independent reconstruction of the expansion history of the Universe and the properties of dark energy

Cited by 107 publications

References 67 publications

Constraints on Dark Energy From Baryon Acoustic Peak and Galaxy Cluster Gas Mass Measurements

Constraints on Dark Energy From Baryon Acoustic Peak and Galaxy Cluster Gas Mass Measurements

Reconstructing the interaction between dark energy and dark matter using Gaussian processes

Post-Planck dark energy constraints

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