Testing the (generalized) Chaplygin gas model with the lookback time-redshift data

Li, Zheng‐Xiang; Wu, Puxun; Yu, Hongwei

doi:10.1088/1475-7516/2009/09/017

Cited by 20 publications

(11 citation statements)

References 79 publications

(55 reference statements)

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“…As a competitive model to explain the lately accelerated expansion of universe, a unified dark fluid (UDF) model [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] was investigated extensively in the recent years. The striking features of the UDF model are that it combines cold dark matter and dark energy and that it behaves like the cold dark matter and the dark energy at an early epoch and a late time, respectively.…”

Section: Introductionmentioning

confidence: 99%

Spherical top-hat collapse of a viscous unified dark fluid

Wei

2014

Eur. Phys. J. C

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In this paper, we test the spherical collapse of a viscous unified dark fluid (VUDF) which has constant adiabatic sound speed and show the nonlinear collapse for VUDF, baryons, and dark matter, which are important in forming the large-scale structure of our Universe. By varying the values of the model parameters α and ζ 0 , we discuss their effects on the nonlinear collapse of the VUDF model, and we compare its result to the CDM model. The results of the analysis show that, within the spherical top-hat collapse framework, larger values of α and smaller values of ζ 0 make the structure formation earlier and faster, and the other collapse curves are almost distinguished with the curve of CDM model if the bulk viscosity coefficient ζ 0 is less than 10 −3 .

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Section: Introductionmentioning

confidence: 99%

Spherical top-hat collapse of a viscous unified dark fluid

Wei

2014

Eur. Phys. J. C

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“…Following this idea, it was considered the so-called generalized Chaplygin gas [8]. This model has been analyzed many times in the literature; see, for example, [9]. Subsequently, this model has been modified to include an initial phase of radiation and is called the modified Chaplygin gas (MCG).…”

Section: Introductionmentioning

confidence: 99%

Fitting Cosmological Data to the Function q(z) from GR Theory: Modified Chaplygin Gas

Velasquez-Toribio

Bedran

2011

Braz J Phys

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In the Friedmann cosmology, the deceleration of the expansion q plays a fundamental role. We derive the deceleration as a function of redshift q(z) in two scenarios: CDM model and modified Chaplygin gas (MCG) model. The function for the MCG model is then fitted to the cosmological data in order to obtain the cosmological parameters that minimize χ 2 . We use the Fisher matrix to construct the covariance matrix of our parameters and reconstruct the q(z) function. We use Supernovae Ia, WMAP5, and BAO measurements to obtain the observational constraints. We determined the present acceleration as q 0 = −0.65 ± 0.19 for the MCG model using the Union2 dataset of SNeIa, BAO, and CMB and q 0 = −0.67 ± 0.17 for the Constitution dataset, BAO and CMB. The transition redshift from deceleration to acceleration was found to be around 0.80 for both datasets. We have also determined the dark energy parameter for the MCG model: X0 = 0.81 ± 0.03 for the Union2 dataset and X0 = 0.83 ± 0.03 using the Constitution dataset.

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“…If one treats the dark energy and dark matter as a unified dark fluid, the corresponding models have been put for-ward and studied in Kunz (2009), Capozziello et al (2006), Hipolito-Ricaldi et al (2010), Ananda & Bruni (2006), Balbi et al (2006), Xu et al (2011Xu et al ( , 2012a, Kamenshchik et al (2001), Barrow (1988), Bento et al (2002Bento et al ( , 2004, Barreiro et al (2008), Li et al (2009), Wu & Yu (2007), Park et al (2010), Liang et al (2011), Xu (2013a,b), Li & Xu (2014a,b), Lu et al (2008), Xu & Lu (2010), Aviles & Cervantes-Cota (2011), Luongo & Quevedo (2012), Camera et al (2009Camera et al ( , 2011, Bertacca et al (2008), Yang & Xu (2013), Bruni et al (2013), Piattella et al (2010), Benaoum (2002), , Bilic et al (2004), Beca & Avelino (2007), Avelino et al (2004Avelino et al ( , 2008Avelino et al ( , 2014, Beca et al (2003), .…”

Section: Introductionmentioning

confidence: 99%

“…In these unified dark fluid models, the Chaplygin gas (CG) and its generalized models have been widely studied in order to explain the accelerating universe in Kamenshchik et al (2001), Barrow (1988), Bento et al (2002Bento et al ( , 2004, Barreiro et al (2008), Li et al (2009), Wu & Yu (2007), Park et al (2010), Xu et al (2011Xu et al ( , 2012b, Liang et al (2011), Xu (2013a,b), Li & Xu (2014a,b), Lu et al (2008), Xu & Lu (2010), Benaoum (2002), , Bilic et al (2004), Avelino et al (2004Avelino et al ( , 2008Avelino et al ( , 2014, Beca & Avelino (2007), Beca et al (2003), . The most interesting property for this kind of scenarios is that two unknown dark sections-dark energy and dark matter can be unified by using an exotic equation of state.…”

Section: Introductionmentioning

confidence: 99%

Astronomical bounds on the modified Chaplygin gas as a unified dark fluid model

Yang

Gai

2019

A&A

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The modified Chaplygin gas could be considered to abide by the unified dark fluid model because the model might describe the past decelerating matter dominated era and at present time it provides an accelerating expansion of the Universe. In this paper, we have employed the Planck 2015 cosmic microwave background anisotropy, type-Ia supernovae, observed Hubble parameter data sets to measure the full parameter space of the modified Chaplygin gas as a unified dark matter and dark energy model. The model parameters Bs, α, and B determine the evolutional history of this unified dark fluid model by influencing the energy density ρMCG = ρMCG0[Bs + (1 − Bs)a−3(1 + B)(1 + α)]1/(1 + α). We assumed the pure adiabatic perturbation of unified modified Chaplygin gas in the linear perturbation theory. In the light of Markov chain Monte Carlo method, we find that Bs = 0.727+0.040+0.075−0.039−0.079, α = −0.0156+0.0982+0.2346−0.1380−0.2180, B = 0.0009+0.0018+0.0030−0.0017−0.0030 at 2σ level. The model parameters α and B are very close to zero and the nature of unified dark energy and dark matter model is very similar to cosmological standard model ΛCDM.

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Testing the (generalized) Chaplygin gas model with the lookback time-redshift data

Cited by 20 publications

References 79 publications

Spherical top-hat collapse of a viscous unified dark fluid

Spherical top-hat collapse of a viscous unified dark fluid

Fitting Cosmological Data to the Function q(z) from GR Theory: Modified Chaplygin Gas

Astronomical bounds on the modified Chaplygin gas as a unified dark fluid model

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