Agegraphic dark energy: growth index and cosmological implications

Malekjani, M.; Basilakos, Spyros; Mehrabi, Ahmad; Davari, Zahra; Rezaei, Mehdi

doi:10.1093/mnras/stw2426

Cited by 38 publications

(59 citation statements)

References 146 publications

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“…Specifically, we implement a statistical analysis using the background expansion data including those of SN Ia ( Basilakos et al 2009b;Hinshaw et al 2013;Mehrabi et al 2015aMehrabi et al , 2017Malekjani et al 2017). In this framework, the joint likelihood function is the product of the individual likelihoods,…”

Section: Background History In Pade Parameterizationsmentioning

confidence: 99%

“…Moreover, the growth of cosmic structures are also affected by perturbations of DE when we deal with dynamical DE models with time varying EoS parameter w 1 de ¹ - (Erickson et al 2002;Bean & Doré 2004;Hu & Scranton 2004;Basilakos & Voglis 2007;Mota et al 2007;Ballesteros & Riotto 2008;Basilakos et al 2009aBasilakos et al , 2010Gannouji et al 2010;Sapone & Majerotto 2012;Batista & Pace 2013;Dossett & Ishak 2013;Basse et al 2014;Batista 2014;Nesseris & Sapone 2015;Pace et al 2014aPace et al , 2014bBasilakos 2015;Mehrabi et al 2015aMehrabi et al , 2015bMehrabi et al , 2015cMalekjani et al 2015Malekjani et al , 2017.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, we can set up a more general formalism in which the background expansion data, including SN Ia, BAO, CMB shift parameter, Hubble expansion data, joined with the growth rate data of LSSs in order to put constraints on the parameters of cosmology and DE models (see Cooray et al 2004;Corasaniti et al 2005;Mota et al 2007Mota et al , 2008Basilakos et al 2010;Gannouji et al 2010;Mota et al 2010;Blake et al 2011b;Nesseris et al 2011;Basilakos & Pouri 2012;Chuang et al 2013;Contreras et al 2013;Llinares & Mota 2013;Llinares et al 2014;Li et al 2014;Yang et al 2014;Basilakos 2015;Mehrabi et al 2015aMehrabi et al , 2015bBasilakos 2016;Bonilla Rivera & Farieta 2016;Fay 2016;Malekjani et al 2017).…”

Section: Introductionmentioning

confidence: 99%

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Constraints to Dark Energy Using PADE Parameterizations

Rezaei

Malekjani

Basilakos

et al. 2017

ApJ

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We put constraints on dark energy (DE) properties using PADE parameterization, and compare it to the same constraints using Chevalier-Polarski-Linder (CPL) and ΛCDM, at both the background and the perturbation levels. The DE equation of the state parameter of the models is derived following the mathematical treatment of PADE expansion. Unlike CPL parameterization, PADE approximation provides different forms of the equation of state parameter that avoid the divergence in the far future. Initially we perform a likelihood analysis in order to put constraints on the model parameters using solely background expansion data, and we find that all parameterizations are consistent with each other. Then, combining the expansion and the growth rate data, we test the viability of PADE parameterizations and compare them with CPL and ΛCDM models, respectively. Specifically, we find that the growth rate of the current PADE parameterizations is lower than ΛCDM model at low redshifts, while the differences among the models are negligible at high redshifts. In this context, we provide for the first time a growth index of linear matter perturbations in PADE cosmologies. Considering that DE is homogeneous, we recover the well-known asymptotic value of the growth index (namely . Finally, we generalize the growth index analysis in the case where γ is allowed to vary with redshift, and we find that the form of z g ( ) in PADE parameterization extends that of the CPL and ΛCDM cosmologies, respectively.

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Section: Background History In Pade Parameterizationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Constraints to Dark Energy Using PADE Parameterizations

Rezaei

Malekjani

Basilakos

et al. 2017

ApJ

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“…These data can reveal the role of DE in the accelerating of the universe expansion. Moreover, since we deal with DDE with time varying EoS parameter w de = −1 the growth rate of cosmic structures can also be affected by perturbations of DE [57][58][59][60][61][62]. We use the background expansion data in conjunction with the growth rate data of large scale structures in order to put constraints on the parameters of cosmology and DE models.…”

Section: Introductionmentioning

confidence: 99%

“…This combination of data have been used in a variety of DE models and studies, see e.g. [see 27,59,60,[63][64][65][66][67].…”

Section: Introductionmentioning

confidence: 99%

Can dark energy be expressed as a power series of the Hubble parameter?

2019

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In this work, we examine the possibility that the dark energy (DE) density, ρ de , can be dynamical and appear as a power series expansion of the Hubble rate (and its time derivatives), i.e. ρ de (H,Ḣ, ...). For the present universe, however, only the terms H,Ḣ and H 2 can be relevant, together with an additive constant term. We fit these models to the current cosmological data on the main observables SnIa+H(z)+BAO+LSS+CMB+BBN. Our analysis involves both the background as well as the cosmic perturbation equations. The latter include, apart from the matter density perturbations, also the DE density perturbations. We assume that matter and dynamical DE are separately self-conserved. As a result the equation of state of the DE becomes a nontrivial function of the cosmological redshift, wD = wD(z). The particular subset of DE models of this type having no additive constant term in ρ de include the so-called "entropic-force" and "QCD-ghost" DE models, as well as the pure linear model ρ de ∼ H, all of which are strongly disfavored in our fitting analysis. In contrast, the models that include the additive term plus one or both of the dynamical componentsḢ and H 2 appear more favored than the ΛCDM. In particular, the dynamical DE models provide a value of σ8 ≃ 0.74 − 0.77 which is substantially lower than that of the ΛCDM and hence more in accordance with the observations. This helps to significantly reduce the σ8-tension in the structure formation data. At the same time the predicted value for H0 is in between the local and Planck measurements, thus helping to alleviate this tension as well.PACS numbers:

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Realisation of cosmic inflation under the purview of f(Q) gravity with agegraphic fluid

Chakraborty

2024

Indian J Phys

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Agegraphic dark energy: growth index and cosmological implications

Cited by 38 publications

References 146 publications

Constraints to Dark Energy Using PADE Parameterizations

Constraints to Dark Energy Using PADE Parameterizations

Can dark energy be expressed as a power series of the Hubble parameter?

Realisation of cosmic inflation under the purview of f(Q) gravity with agegraphic fluid

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