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Related papers: Generalizing the generalized Chaplygin gas

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We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded.…

Astrophysics · Physics 2009-10-29 M. C. Bento , O. Bertolami , A. A. Sen

We develop a cosmological model based on a quadratic equation of state p/c^2=-(\alpha+1){\rho^2}/{\rho_P}+\alpha\rho-(\alpha+1)\rho_{\Lambda} (where \rho_P is the Planck density and \rho_{\Lambda} the cosmological density) "unifying" vacuum…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-01 Pierre-Henri Chavanis

Unified dark matter models are appealing in that they describe the dark sector in terms of a single component. They however face problems when attempting to account for structure formation: in the linear regime, density fluctuations can…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Amr El-Zant

We discuss dark energy models which might describe effectively the actual acceleration of the universe. More precisely, for a 4-dimensional Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) universe we consider two situations: First of them,…

Astrophysics · Physics 2008-11-26 Mariam Bouhmadi-Lopez , Jose A. Jimenez Madrid

We explore the properties of dark energy models for which the equation-of-state, w, defined as the ratio of pressure to energy density, crosses the cosmological-constant boundary w = -1. We adopt an empirical approach, treating the dark…

Astrophysics · Physics 2010-04-06 Robert R. Caldwell , Michael Doran

We extend the Chaplygin gas model for dark matter and dark energy unification by promoting the Chaplygin gas parameter A to the potential for an extra scalar with canonical kinetic energy. The hybrid model allows for accelerated Hubble…

Astrophysics · Physics 2009-11-10 Neven Bilic , Gary B. Tupper , Raoul D. Viollier

We model the cosmic medium as the mixture of a generalized Chaplygin gas and a pressureless matter component. Within a neo-Newtonian approach (in which, different from standard Newtonian cosmology, the pressure enters the homogeneous and…

Astrophysics · Physics 2010-04-15 J. C. Fabris , S. V. B. Goncalves , H. E. S. Velten , W. Zimdahl

We have explored the possibility of the co-existence of two forms of dark energy in the form of an alternative Generalized Chaplygin Gas (GCG) along with a scalar field of field theoretic or extra dimensional origin in the background of a…

General Relativity and Quantum Cosmology · Physics 2026-01-28 Mahasweta Biswas , Rikpratik Sengupta , Ujjal Debnath

We study a generalized version of Chaplygin gas as unified model of dark matter and dark energy. Using realistic theoretical models and the currently available observational data from the age of the universe, the expansion history based on…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Chan-Gyung Park , Jai-chan Hwang , Jaehong Park , Hyerim Noh

We investigate observational constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Union SNe Ia data, the observational Hubble data, the SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jianbo Lu , Yuanxing Gui , Lixin Xu

In this paper, we investigate cosmological models of the extended Chaplygin gas in a universe governed by Horava-Lifshitz gravity. The equation of state for an extended Chaplygin gas is a $(n+2)$-variable equation determined by $A_{n}$,…

General Relativity and Quantum Cosmology · Physics 2016-07-08 B. Pourhassan

The thermodynamic properties of dark energy-dominated universe in the presence of a black hole are investigated in the general case of a varying equation-of-state-parameter $w(a)$. We show that all the thermodynamics quantities are regular…

General Relativity and Quantum Cosmology · Physics 2015-03-14 Khireddine Nouicer

The generalized Chaplygin gas (GCG) model in spatially flat universe is investigated. The cosmological consequences led by GCG model including the evolution of EoS parameter, deceleration parameter and dimensionless Hubble parameter are…

General Relativity and Quantum Cosmology · Physics 2011-06-10 M. Malekjani , A. Khodam-Mohammadi , N. Nazari-Pooya

In this Letter, a modified Chaplygin gas (MCG) model of unifying dark energy and dark matter with the exotic equation of state $p_{MCG}=B\rho_{MCG} -\frac A{\rho_{MCG}^\alpha}$ is constrained from recently observed data: the 182 Gold SNe…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 Jianbo Lu , Lixin Xu , Jiechao Li , Baorong Chang , Yuanxing Gui , Hongya Liu

We examine the properties of dark energy and dark matter through the study of the variation of the electromagnetic coupling. For concreteness, we consider the unification model of dark energy and dark matter, the generalized Chaplygin gas…

Astrophysics · Physics 2008-11-26 M. C. Bento , O. Bertolami , P. Torres

We investigate the evolution of a FRW model fuelled by a modified Chaplygin gas with an equation of state $p = A\rho -\frac{B}{\rho^\alpha}$. An attempt is made here to constrain the free parameters of MCG model through the wellknown…

General Relativity and Quantum Cosmology · Physics 2015-10-23 D. Panigrahi , B. C. Paul , S. Chatterjee

Accelerating Chaplygin gas combined with the decelerating braneworld Dvali-Gabadadze-Porrati (DGP) model can produce an overall accelerated expansion of the order of magnitude seen. Both models have similar asymptotic properties at early…

Astrophysics · Physics 2008-12-18 Matts Roos

We constrain the parameters of the variable Chaplygin gas model, using the location of peaks of the CMBR spectrum and SNe Ia ``gold '' data set. Equation of state of the model is $P=-A(a)/\rho$, where $A(a)=A_0 a^{-n}$ is a positive…

Astrophysics · Physics 2008-11-26 Geetanjali Sethi , Sushil K. Singh , Pranav Kumar , Deepak Jain , Abha Dev

A new class of braneworld models displaying late-time phantom acceleration without resorting to a phantom fluid is presented. In this scenario expansion is fuelled by dark matter together with some effective dark energy capable of crossing…

Astrophysics · Physics 2008-11-26 Mariam Bouhmadi-López , Ruth Lazkoz

In this paper, we reexamine the generalized Chaplygin gas (GCG) cosmology with the sign-changeable interaction. The dynamical analysis show that there exists de-Sitter attractors in this model, which means that the late-time behaviors of…

General Relativity and Quantum Cosmology · Physics 2015-10-13 Ping Xi , Ping Li