Current observational constraints to the holographic dark energy model with a new infrared cutoff via the Markov chain Monte Carlo method

Wang, Yuting; Xu, Lixin

doi:10.1103/physrevd.81.083523

Cited by 75 publications

(21 citation statements)

References 82 publications

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“…depending on positive or negative value of λ. Especially, substituting the observational values of model parameters α = 0.8502 and β = 0.4817 [76] along with ω d = −0.5, H 0 = 1, we get ζ 0 + ζ 1 = 0.096 for positive value of λ = 0.06 and ζ 0 + ζ 1 = 0.218 for negative value of λ = −0.06, respectively. Thus, for the present time transition from deceleration to acceleration takes place at ζ 0 + ζ 1 = 0.096 for positive values of λ = 0.06 and for negative value of λ = −0.06, we get ζ 0 + ζ 1 = 0.218.…”

Section: Evolution Of the Scale Factormentioning

confidence: 82%

New holographic dark energy model with bulk viscosity in f(R, T) gravity

Singh

Srivastava

2019

Indian J Phys

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In this paper, bulk viscosity is introduced in new holographic dark energy (HDE) to describe the effects of cosmic non-perfect fluid on the evolution of the universe in modified f (R, T ) gravity. Assuming f (R, T ) = R+λT , where R is the Ricci scalar, T , the trace of energy-momentum tensor and λ is a constant, we derive a general function of Hubble parameter with bulk viscous form to provide a procedure for the viscous new HDE model building. Especially, we assume the total bulk viscosity coefficient proportional to the velocity of the expansion of the universe in such a way that ζ = ζ 0 + ζ 1 H. We obtain the solutions of the scale factor and deceleration parameter and classify all the possible scenarios (deceleration, acceleration and their transition) with different parameter regions chosen properly for positive and negative ranges of λ, and ζ 0 and ζ 1 to analyze the evolution of the universe. It is observed that there is a transition from decelerated phase to accelerated phase at early or late time depending on the values of viscous terms. For large values of viscous terms it always accelerates through out the evolution. Furthermore, we also investigate the statefinder pair {r, s} and Om diagnostics for the viscous new HDE model to discriminate with other existing DE models. The model evolution behaviors are shown in the planes of r − s, r − q and Om − z. It is found that behavior of trajectories in different planes depend on the bulk viscous coefficient. A small combination of ζ 0 and ζ 1 gives the quintessence like behavior whereas large combination of these two terms give Chaplygin gas like model. However, both the model approaches to ΛCDM model in late time of evolution of the universe. Our viscous model is also different from other existing dark energy models. The evolution of effective equation of state parameter is -0.9745 which is very close to the observation. The entropy and generalized second law of thermodynamics are valid for this model under some constraints of bulk viscous coefficient. The analysis shows that the dark energy phenomena may be explained as the effect of bulk viscosity in the cosmic medium.

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Section: Evolution Of the Scale Factormentioning

confidence: 82%

New holographic dark energy model with bulk viscosity in f(R, T) gravity

Singh

Srivastava

2019

Indian J Phys

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“…For flat case, which we are going to consider in this study, the best estimated values for and are ∼ 0.8502 and ∼ 0.4817 as mentioned in [18]. Actually, dark energy theories use Granda-Oliveros scale as IR scale depending only on local quantities; that way it is possible to avoid the causality problem; moreover it is also possible to obtain the accelerated expansion mode of the universe [17].…”

Section: Introductionmentioning

confidence: 87%

Tsallis Holographic Dark Energy with Granda-Oliveros Scale in (n+1)-Dimensional FRW Universe

Aly

2019

Advances in Astronomy

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Based on Tsallis holographic dark energy model recently proposed by using the general model of the Tsallis entropy expression, we reconstruct cosmographic parameters, q,j,κ,l, and we study their evolution in spatially flat (n+1)-dimensional Friedmann-Robertson-Walker universe using Granda-Oliveros scale. Our results show that the universe is in an accelerating expansion mode described by phantom-like behavior. We go further and study the state finder operators and the Om diagnostic to understand the behavior of our model. The stability of the system is also studied by using the square of speed of sound showing that our model is stable over the low range of red-shift considered. The results indicate that the entropy formalism will play an important role in understanding the dynamics of our universe.

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“…This is because the values for these parameters which best fit the observational data have been obtained [42]. These value for a non-flat universe are given by [42],…”

Section: Models For Dark Energymentioning

confidence: 98%

“…These value for a flat universe are given by [42], It may be noted that for Granda-Oliveros model, energy density ρ D can be written as…”

Section: Models For Dark Energymentioning

confidence: 99%

Cosmological reconstruction andOmdiagnostic analysis of Einstein-Aether theory

Pasqua

Chattopadhyay²,

Momeni

et al. 2017

J. Cosmol. Astropart. Phys.

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Abstract. In this paper, we will analyse the cosmological models in Einstein-aether gravity, which is a modified theory of gravity in which a time-like vector field breaks the Lorentz symmetry. We will use this formalism to analyse different cosmological models with different behavior of the scale factor. In this analysis, we will use a certain functional dependence of the dark energy on the Hubble parameter. It will be demonstrated that the aether vector field has a non-trivial effect on these cosmological models. We will also perform the Om diagnostic in Einstein-aether gravity. Thus, we will fit parameters of the cosmological models using recent observational data.

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Current observational constraints to the holographic dark energy model with a new infrared cutoff via the Markov chain Monte Carlo method

Cited by 75 publications

References 82 publications

New holographic dark energy model with bulk viscosity in f(R, T) gravity

New holographic dark energy model with bulk viscosity in f(R, T) gravity

Tsallis Holographic Dark Energy with Granda-Oliveros Scale in (n+1)-Dimensional FRW Universe

Cosmological reconstruction andOmdiagnostic analysis of Einstein-Aether theory

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