Constraints on a generalized deceleration parameter from cosmic chronometers

Mamon, Abdulla Al

doi:10.1142/s0217732318500566

Cited by 60 publications

(37 citation statements)

References 57 publications

(78 reference statements)

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“…There are several parameterizations for q(z) reported in the literature, see refs. [17][18][19][20][21][22][23][25][26][27][28][29][30]. We propose a new one as follows where, q 0 and q 1 are the values for the deceleration parameter at the present epoch, and at high redshift, respectively.…”

Section: Proposed Parameterization For the Deceleration Parametermentioning

confidence: 99%

Constraints on barotropic dark energy models by a new phenomenological q(z) parameterization

et al. 2019

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In this paper, we propose a new phenomenological two parameter parametrization of q(z) to constrain barotropic dark energy models by considering a spatially flat FRW universe, neglecting the radiation component, and reconstructing the effective equation of state (EoS). This two free-parameter EoS reconstruction shows a non-monotonic behavior, pointing to a more general fitting for the scalar field models, like thawing and freezing models. We constrain the q(z) free parameters using the observational data of the Hubble parameter obtained from cosmic chronometers, the joint-light-analysis type Ia Supernovae sample and a joint analysis from these data. We obtain a value of q(z) today, q 0 = −0.48 +0.10 −0.11 , and a transition redshift, z t = 0.71 +0.12 −0.12 (when the Universe change from an decelerated phase to an accelerated one). The effective EoS reconstruction and the ω -ω plane analysis pointed out a quintom dark energy, which is consistent with a non parametric EoS reconstruction, reported by other authors, and using the latest cosmological observations.

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Section: Proposed Parameterization For the Deceleration Parametermentioning

confidence: 99%

Constraints on barotropic dark energy models by a new phenomenological q(z) parameterization

et al. 2019

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“…In this sense, some used different parametric form of q, cf. [11][12][13][14][15][16][17], others used nonparametric forms of q, c.f. [10,[18][19][20][21][22].…”

Section: Dynamical View Of the Modified Friedmann Equationsmentioning

confidence: 99%

Phenomenological reconstruction of f(T) teleparallel gravity

Hanafy

Nashed

2019

Phys. Rev. D

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We present a novel reconstruction method of f (T ) teleparallel gravity from phenomenological parametrizations of the deceleration parameter or other alternatives. This can be used as a toolkit to produce viable modified gravity scenarios directly related to cosmological observations. We test two parametrizations of the deceleration parameter considered in recent literatures in addition to one parametrization of the effective (total) equation of state (EoS) of the universe. We use the asymptotic behavior of the matter density parameter as an extra constraint to identify the viable range of the model parameters. One of the tested models shows how tiny modification can produce viable cosmic scenarios quantitatively similar to ΛCDM but qualitatively different whereas the dark energy (DE) sector becomes dynamical and fully explained by modified gravity not by a cosmological constant.

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“…Also, the equation (3) is useful when the parametric form of the deceleration parameter q(z) is given. In fact, a variety of q-paramertized models have been proposed in the literature (for details see [30,31,43,[49][50][51][52][53][54][55][56][57][58][59][60][61][62]). Following this line of thought, in the present work, we are interested to investigate the evolution of j for a general q-parametrized model given in [57].…”

Section: The Kinematic Modelmentioning

confidence: 99%

“…It is worth noting here that the generalized parametrization is not valid at α = 0. The interesting cosmological characteristics of the parametrization, as given in equation (4), are extensively discussed in [57]. Our main goal in this paper is to examine some simple kinematic model for the cosmic expansion based on the parameterization for q(z) in equation (4).…”

Section: The Kinematic Modelmentioning

confidence: 99%

Observational constraints on the jerk parameter with the data of the Hubble parameter

Mamon

Bamba

2018

Eur. Phys. J. C

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We study the accelerated expansion phase of the universe by using the kinematic approach. In particular, the deceleration parameter q is parametrized in a model-independent way. Considering a generalized parametrization for q, we first obtain the jerk parameter j (a dimensionless third time derivative of the scale factor) and then confront it with cosmic observations. We use the latest observational dataset of the Hubble parameter H(z) consisting of 41 data points in the redshift range of 0.07 ≤ z ≤ 2.36, larger than the redshift range that covered by the Type Ia supernova. We also acquire the current values of the deceleration parameter q0, jerk parameter j0 and transition redshift zt (at which the expansion of the universe switches from being decelerated to accelerated) with 1σ errors (68.3% confidence level). As a result, it is demonstrate that the universe is indeed undergoing an accelerated expansion phase following the decelerated one. This is consistent with the present observations. Moreover, we find the departure for the present model from the standard ΛCDM model according to the evolution of j. Furthermore, the evolution of the normalized Hubble parameter is shown for the present model and it is compared with the dataset of H(z).

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Constraints on a generalized deceleration parameter from cosmic chronometers

Cited by 60 publications

References 57 publications

Constraints on barotropic dark energy models by a new phenomenological q(z) parameterization

Constraints on barotropic dark energy models by a new phenomenological q(z) parameterization

Phenomenological reconstruction of f(T) teleparallel gravity

Observational constraints on the jerk parameter with the data of the Hubble parameter

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