Observational constraint on generalized Chaplygin gas model

Lu, Jianbo; Gui, Yuanxing; Xu, Lixin

doi:10.1140/epjc/s10052-009-1118-8

Cited by 62 publications

(54 citation statements)

References 68 publications

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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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“…The so-called general Chaplygin gas model (GCG) has been widely studied to explain the accelerating Universe [21,22,50]. In the GCG model, the dark sectors in the Universe, i.e., dark energy and dark matter, can be unified through an exotic equation of state.…”

Section: Gcg Modelmentioning

confidence: 99%

Testing and selecting cosmological models with ultra-compact radio quasars

Cao

Zheng

et al. 2017

Eur. Phys. J. C

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In this paper, we place constraints on four alternative cosmological models under the assumption of the spatial flatness of the Universe: CPL, EDE, GCG and MPC. A new compilation of 120 compact radio quasars observed by very-long-baseline interferometry, which represents a type of new cosmological standard rulers, are used to test these cosmological models. Our results show that the fits on CPL obtained from the quasar sample are well consistent with those obtained from BAO. For other cosmological models considered, quasars provide constraints in agreement with those derived with other standard probes at 1σ confidence level. Moreover, the results obtained from other statistical methods including figure of merit, Om(z) and statefinder diagnostics indicate that: (1) Radio quasar standard ruler could provide better statistical constraints than BAO for all cosmological models considered, which suggests its potential to act as a powerful complementary probe to BAO and galaxy clusters. (2) Turning to Om(z) diagnostics, CPL, GCG and EDE models cannot be distinguished from each other at the present epoch. (3) In the framework of statefinder diagnostics, MPC and EDE will deviate from the CDM model in the near future, while GCG model cannot be distinguished from the CDM model unless much higher precision observations are available.

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“…In particular, Scherrer (2006) discussed GCG model with the parameter α > 0 and obtained w < 3w(1 + w) in the w-w plane. However, the latest observational data has given the best fit value α = −0.09 +0.26 −0.19 at 95% confidence level (Lu et al 2009) for GCG model in a flat universe which has shown α < 0 is very possible. In this paper, we have extended the range of the parameter α to −0.28 < α < 0 and found 3w(1 + w) < w < w(1 + w) which satisfies the limit derived in Caldwell and Linder (2005) for "freezing" quintessence model.…”

Section: Introductionmentioning

confidence: 98%

Generalized Chaplygin gas model with or without viscosity in the w–w′ plane

Huang

Zhai

2011

Astrophys Space Sci

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In this paper, we investigate the dynamics of generalized Chaplygin gas (GCG) model with or without viscosity in the w-w plane, which is defined by the equation of state parameter and its time derivative with respect to the logarithm of the scale factor. We show that GCG model without viscosity approaches to a late time de Sitter attractor (w g = −1) and behaves like a "freezing" scalar field for the parameter α constrained by the latest observational data. However, introducing viscosity exerts an influence on the evolution of w and affects the location of the late time attractor (w g > −1) in viscous GCG model. We also find numerically such a transition from w > 0 to w < 0 as the universe expands in viscous GCG model different from GCG model without viscosity (w < 0) in the w-w plane.

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Observational constraint on generalized Chaplygin gas model

Cited by 62 publications

References 68 publications

Spherical top-hat collapse of a viscous unified dark fluid

Spherical top-hat collapse of a viscous unified dark fluid

Testing and selecting cosmological models with ultra-compact radio quasars

Generalized Chaplygin gas model with or without viscosity in the w–w′ plane

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