Observational constraints of modified Chaplygin gas in loop quantum cosmology

Chakraborty, Shuvendu; Debnath, Ujjal; Ranjit, Chayan

doi:10.1140/epjc/s10052-012-2101-3

Cited by 35 publications

(15 citation statements)

References 44 publications

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“…There are also other constraints for example those reported by the Refs. [77,78,79,80]. It is possible to consider B as a variable (depending on the time t) instead of a constant.…”

Section: The Modelsmentioning

confidence: 99%

Higher order corrections of the extended Chaplygin gas cosmology with varying $$G$$ G and $$\Lambda $$ Λ

et al. 2015

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In this paper, we study two different models of dark energy based on the Chaplygin gas equation of state. The first model is the variable modified Chaplygin gas, while the second one is the extended Chaplygin gas. Both models are considered in the framework of higher order f (R) modified gravity. We also consider the case of time-varying gravitational constant G and for both models. We investigate some cosmological parameters such as the Hubble, the deceleration, and the equation of state parameters. Then we show that the model that we consider, the extended Chaplygin gas with time-dependent G and , is consistent with the observational data. Finally we conclude with the discussion of cosmological perturbations of our model.

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“…There are also other constraints for example those reported by the Refs. [77,78,79,80]. It is possible to consider B as a variable (depending on the time t) instead of a constant.…”

Section: The Modelsmentioning

confidence: 99%

Higher order corrections of the extended Chaplygin gas cosmology with varying $$G$$ G and $$\Lambda $$ Λ

et al. 2015

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“…In modern cosmology, the cosmic coincidence problem by taking Chaplygin gas into account with dark matter was studied by Jamil et al [58]. Chakraborty et al [59], explored the modified Chaplygin gas in LQC. It is also found that with the help of Loop quantum effects one can avoid the future singularities appearing in the standard cosmology.…”

Section: Basic Equationsmentioning

confidence: 99%

Tsallis, Rényi and Sharma-Mittal Holographic Dark Energy Models in Loop Quantum Cosmology

et al. 2018

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The cosmic expansion phenomenon is being studied through the interaction of newly proposed dark energy models (Tsallis, Rényi and Sharma-Mittal holographic dark energy (HDE) models) with cold dark matter in the framework of loop quantum cosmology. We investigate different cosmic implications such as equation of state parameter, squared sound speed and cosmological plane (ω d -ω d , ω d and ω d represent the equation of state (EoS) parameter and its evolution, respectively). It is found that EoS parameter exhibits quintom like behavior of the universe for all three models of HDE. The squared speed of sound represents the stable behavior of Rényi HDE and Sharma-Mittal HDE at the latter epoch while unstable behavior for Tsallis HDE. Moreover, ω d -ω d plane lies in the thawing region for all three HDE models.Symmetry 2018, 10, 635 2 of 15 theory where T is the trace of the energy-momentum tensor [37], etc. For recent reviews on modified gravity theories and dark energy problem, see, for instance [14,30,[38][39][40][41].The HDE is a promising candidate of DE, which has been studied extensively in the literature. It is based upon the holographic principle [29,42,43] that states the number of degrees of freedom of a system scales with its area instead of its volume. Cohen et al. studied that the DE should obey the holographic principle and constrained by the infrared (IR) cut-off [44]. Li has examined three choices for the IR cutoff as the Hubble horizon, the future event horizon and the particle horizon and also shown that only the future event horizon is able to provide the sufficient acceleration for the universe [45]. Sheykhi [46], developed the HDE model with Hubble horizon and argued that this model possesses the ability to explain the present state of the universe with the help of interaction of DE and cold dark matter (CDM).Hu and Ling [47] studied the relationship between interacting, HDE and cosmological parameters through observational constraints. They investigated that HDE model is justified with the present observations in the low redshift region. They also tried to reduce the cosmic coincidence problem by taking different possibilities of time rate of change of the ratio of dark matter to HDE densities for a particular choice of interacting term. Ma et al. [48] explored observational signatures of interacting and non-interacting HDE with dark matter. In these models they also observed the big rip singularity in for different parameters by using a lot of recent observational schemes. They also found that the HDE models are slightly compatible with the observations as compared to the ΛCDM model.In the context of thermodynamics, horizon entropy and DE can be effected by each other. Recently, due to the long-range nature of gravity, the mysterious nature of spacetime and pushed by the fact that the Bekenstein entropy is a non-extensive entropy measure. The generalized entropies, i.e., Tsallis and Rényi entropies have been assigned to the horizons to study the cosmological and gravitational phenomenon.To stu...

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“…It has also been found that the future singularity appearing in the standard FRW cosmology can be avoided by loop quantum effects [43]. Chakraborty et al [44] have tested MCG in LQC. The modified Einstein's field equations in LQC for FRW metric are given by…”

Section: Sthc For Vmvcg In Loop Quantum Cosmologymentioning

confidence: 99%

Viscous Chaplygin gas models as spherical top-hat collapsing fluids

Jawad

Iqbal

2016

Int. J. Mod. Phys. D

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We study the spherical top-hat collapse in Einstein gravity and loop quantum cosmology by taking the non-linear evolution of viscous modified variable chaplygin gas and viscous generalized cosmic chaplygin gas. We calculate the equation of state parameter, square speed of sound, perturbed equation of state parameter, perturbed square speed of sound, density contrast and divergence of peculiar velocity in perturbed region and discussed their behavior. It is observed that both chaplygin gas models support the spherical collapse in Einstein as well as loop quantum cosmology because density contrast remains positive in both cases and the perturbed equation of state parameter remains positive at the present epoch as well as near future. It is remarked here that these parameters provide the consistence results for both chaplygin gas models in both gravities.

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Observational constraints of modified Chaplygin gas in loop quantum cosmology

Abstract: We have considered the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter (perfect fluid with negligible pressure) and the modified Chaplygin we concluded that our model is in agreement with the union2 sample data.

Cited by 35 publications

References 44 publications

Higher order corrections of the extended Chaplygin gas cosmology with varying $$G$$ G and $$\Lambda $$ Λ

Higher order corrections of the extended Chaplygin gas cosmology with varying $$G$$ G and $$\Lambda $$ Λ

Tsallis, Rényi and Sharma-Mittal Holographic Dark Energy Models in Loop Quantum Cosmology

Viscous Chaplygin gas models as spherical top-hat collapsing fluids

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