English
Related papers

Related papers: Viscous generalized Chaplygin gas

200 papers

We extend the equation of state of GCG (Generalized Chaplygin Gas) to $w<-1$ regime and show, from the point of view of dynamics, that the parameters of GCG should be in the range of $0<\alpha<1$. Also, dynamical analysis indicate that the…

Astrophysics · Physics 2009-11-10 Jian-gang Hao , Xin-zhou Li

The generalized Chaplygin gas, which interpolates between a high density relativistic era and a non-relativistic matter phase, is a popular dark energy candidate. We consider a generalization of the Chaplygin gas model, by assuming the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 C. S. J. Pun , L. Á. Gergely , M. K. Mak , Z. Kovács , G. M. Szabó , T. Harko

We use the hybrid model of bulk viscosity and generalized chaplygin gas (GCG), named the viscous generalized chaplygin gas (VGCG) model, which is thought to be an alternate dark fluid of the universe. We explore the dynamics of the VGCG…

General Relativity and Quantum Cosmology · Physics 2023-03-13 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

The viability of the variable generalised Chaplygin gas (VGCG) model is analysed from the standpoint of its thermodynamical stability criteria with the help of an equation of state, $P = - \frac{B}{\rho^{\alpha}}$, where $B =…

General Relativity and Quantum Cosmology · Physics 2017-02-17 D. Panigrahi , S. Chatterjee

The generalized Chaplygin gas (GCG) model allows for an unified description of the cosmologically recent accelerated expansion of the Universe and of the evolution of energy density perturbations. This dark energy - dark matter unification…

Astrophysics · Physics 2007-05-23 O. Bertolami

In this paper, we continue our previous work of studying viscous generalized Chaplygin gas (VGCG) as a unified dark fluid but including the bulk viscosity perturbation. By using the currently available cosmic observational data from SNLS3,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-03 Wei Li , Lixin Xu

Motivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 A. Hernández-Almada , Miguel A. García-Aspeitia , M. A. Rodrírgues-Meza , V. Motta

The generalized Chaplygin gas (GCG) model explains the recent accelerated expansion of the Universe via an exotic background fluid whose equation of state is given by p=-A/\rho^\alpha, where A is a positive constant and 0<\alpha\le 1. The…

Astrophysics · Physics 2015-06-24 M. C. Bento , O. Bertolami , A. A. Sen

We apply methods of dynamical systems to study the behaviour of universe dominated by the generalized Chaplygin gas. We reduce the dynamics to a 2-dimensional Hamiltonian system and study its behaviour for various ranges of parameters. The…

Astrophysics · Physics 2009-11-10 Marek Szydlowski , Wojciech Czaja

Recently developed Generalized Cosmic Chaplygin gas (GCCG) is studied as an unified model of dark matter and dark energy. To explain the recent accelerating phase, the Universe is assumed to have a mixture of radiation and GCCG. The mixture…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Writambhara Chakraborty , Ujjal Debnath , Subenoy Chakraborty

Addressing the late-time accelerated expansion of the universe, known as the "dark energy problem", remains a central challenge in cosmology. While the cosmological constant is the standard explanation, alternative models such as…

General Relativity and Quantum Cosmology · Physics 2025-10-27 Gilberto Aguilar-Pérez , Miguel Cruz , Mohsen Fathi , Daniel de Jesús García-Castro , J. R. Villanueva

In this paper, viscous generalized Chaplygin gas as a model of dark energy considered. We assume non-constant bulk viscous coefficient and study dark energy density. We consider several cases of density-dependent viscosities. We find that,…

General Relativity and Quantum Cosmology · Physics 2014-03-10 H. Saadat , B. Pourhassan

In this paper, we propose extended Chaplygin gas equation of state for which it recovers barotropic fluid with quadratic equation of state. We use numerical method to investigate the behavior of some cosmological parameters such as scale…

General Relativity and Quantum Cosmology · Physics 2014-09-17 B. Pourhassan , E. O. Kahya

The generalized Chaplygin gas (GCG), which has an unusual perfect fluid equation of state, is another promising candidate for dark energy. We investigate the GCG scenario coupled with a baryonic matter in a newly suggested $f(Q,T)$ gravity,…

General Relativity and Quantum Cosmology · Physics 2022-06-24 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

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

We study the cosmological scenario arising from the dynamics of a generalized Chaplygin gas. The equation of state of the system is given in terms of the energy density, $\rho$, and pressure, $p$, by the relationship $p = -…

Astrophysics · Physics 2007-05-23 M. C. Bento , O. Bertolami , A. A. Sen

The generalized Chaplygin gas (GCG) model allows for an unified description of the recent accelerated expansion of the Universe and the evolution of energy density perturbations. This dark energy - dark matter unification is achieved…

General Relativity and Quantum Cosmology · Physics 2014-11-17 M. C. Bento , O. Bertolami , A. A. Sen

In this paper, we investigate the viscous modified Chaplygin gas cosmological model. Solutions for different values of the viscosity parameter are obtained using both analytical and numerical methods. We have calculated the deceleration and…

General Relativity and Quantum Cosmology · Physics 2014-09-16 H. B. Benaoum

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

The cosmological observations suggest that the presently accelerating universe should be filled by an exotic form of matter, violating the strong energy condition, of unknown nature and origin. We propose the viscous dark matter of a source…

General Relativity and Quantum Cosmology · Physics 2020-08-05 Marek Szydlowski , Adam Krawiec
‹ Prev 1 2 3 10 Next ›