Constraints to Dark Energy Using PADE Parameterizations

Rezaei, Mehdi; Malekjani, M.; Basilakos, Spyros; Mehrabi, Ahmad; Mota, David F.

doi:10.3847/1538-4357/aa7898

Cited by 72 publications

(63 citation statements)

References 152 publications

(243 reference statements)

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“…For all considered models we have also founded the redshift, for which the Universe starts to accelerate. The results vary from z tr = 0.9 (for the case 1) to z tr = 0.66 for the ΛCDM, all in good agreement with recent works [71][72][73]77].…”

Section: Discussionsupporting

confidence: 90%

New parametrization for unified dark matter and dark energy

2018

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In this paper we investigate a new phenomenological parameterization for unified dark matter and dark energy based on the polynomial expansion of the barotropic equation of state parameter w. Our parameterization provides well-behaving evolution of w for both small and big redshifts as well as in the far future. The dark fluid described by our parameterization behaves for big redshifts like a dark matter. Therefore one can parameterize dark energy and dark matter using a single dark fluid, like in the case of the Chaplygin gas. Within this parameterization we consider 2 models: one with DE barotropic parameter fixed to be −1 and the second one, where w = −1 is chosen to match the best fit to the data. We study main cosmological properties of these models at the expansion and perturbation levels. Based on Markov chain Monte Carlo method with currently available cosmic observational data sets, we constrain these models to determine the cosmological parameters at the level of background and clustering of matter. We consider the interaction between DM and DE which directly affects the evolution of matter and its clustering. Our model appears to be perfectly consistent with the ΛCDM model, while providing unification of DE and DM. * Electronic address: z.davaridolatabadi@sci.basu.ac.ir † Electronic address: malekjani@basu.ac.ir

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Section: Discussionsupporting

confidence: 90%

New parametrization for unified dark matter and dark energy

2018

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“…We found that the Hubble parameter in HDE cosmologies is ∼ 0.9 − 1.2% smaller than the ΛCDM model at low redshifts. We also showed that in HDE, cosmologies the universe changes its phase from decelerating to accelerating expansion at z tr ∼ 0.7 which in 1σ error is consistent with observations [see also 83,[113][114][115].…”

Section: Discussionsupporting

confidence: 89%

Can holographic dark energy models fit the observational data?

2018

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In this work we investigate the holographic dark energy models with slowly time-varying model parameter defined based on the current Hubble horizon length scale. While the previous studies on the three popular holographic dark energy models defined based on the future event horizon, Ricci scale and Granda-Oliveros IR cutoffs showed that these models cannot fit the observational data [1], in this work we show that the holographic dark energy models with time-varying model parameter defined on the current Hubble radius are well favored by observations. Using the standard χ 2 minimization in the context of Markov Chain Monte Carlo method, we compare the ability of holographic dark energy models with time-varying c 2 parameter constructed on the current Hubble length scale against different sets of observational data namely expansion data, growth rate data and expansion+growth rate data respectively. Based on the values of Akaike and Bayesian information criteria, we find that these types of holographic dark energy models are well fitted to both expansion and growth rate observations as equal to ΛCDM cosmology. We also put constraints on the cosmological parameters and show that the transition epoch form early decelerated to current accelerated expansion calculated in holographic dark energy models with time-varying model parameter defined on the Hubble length is consistent with observations.

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“…and the model of order (0, 2) gives H 0 = 68.8 ± 2.0 km/s/Mpc (68% C.L. ), both of which are in good accordance with the results from different analysis that employ the Padé parameterization (Rezaei et al 2017;Mehrabi & Basilakos 2018;Capozziello & Sen 2019).…”

Section: Resultssupporting

confidence: 88%

Model-independent Determination of Cosmic Curvature Based on the Padé Approximation

Zhang

et al. 2019

ApJ

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Given observations of the standard candles and the cosmic chronometers, we apply Padé parameterization to the comoving distance and the Hubble paramter to find how stringent the constraint is set to the curvature parameter by the data. A weak informative prior is introduced in the modeling process to keep the inference away from the singularities. Bayesian evidence for different order of Padé parameterizations is evaluated during the inference to select the most suitable parameterization in light of the data. The data we used prefer a parameterization form of comoving distance as D 01 (z) = a0z 1+b1z as well as a competitive form D 02 (z) = a0z 1+b1z+b2z 2 . Similar constraints on the spatial curvature parameter are established by those models and given the Hubble constant as a byproduct: Ω k = 0.25 +0.14 −0.13 (68% confidence level [C.L.]), H 0 = 67.7 ± 2.0 km/s/Mpc (68% C.L.) for D 01 , and Ω k = −0.01 ± 0.13 (68% C.L.), H 0 = 68.8 ± 2.0 km/s/Mpc (68% C.L.) for D 02 . The evidence of different models demonstrates the qualitative analysis of the Padé parameterizations for the comoving distance.

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Constraints to Dark Energy Using PADE Parameterizations

Cited by 72 publications

References 152 publications

New parametrization for unified dark matter and dark energy

New parametrization for unified dark matter and dark energy

Can holographic dark energy models fit the observational data?

Model-independent Determination of Cosmic Curvature Based on the Padé Approximation

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