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In this paper, we consider an open system from the thermodynamic perspective for an adiabatic FRW universe model in which particle creation occurs within the system. In that case, the modified continuity equation is obtained and then we…

General Relativity and Quantum Cosmology · Physics 2022-12-14 S. Ganjizadeh , Alireza Amani , M. A. Ramzanpour

We study the main cosmological properties of the Generalized Chaplygin Gas (GCG) dark energy model at the background and perturbation levels. By using the latest cosmological data in both the background and perturbation levels, we implement…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 S. F. Salahedin , M. Malekjani , K. Y. Roobiat , R. Pazhouhesh

The Hubble diagram (HD) of Gamma-Ray Bursts (GRBs) having properly estimated redshifts is compared with the predicted one for the Chaplygin gas (CG), a dark energy candidate. The CG cosmology and that of Friedmann and $\Lambda$-CDM models…

We constrain a unified dark matter (UDM) model from the latest observational data. This model assumes that the dark sector is degenerate. Dark energy and dark matter are the same component. It can be described by an affine equation of state…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-11 Kai Liao , Shuo Cao , Jun Wang , Xiaolong Gong , Zong-Hong Zhu

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 construct modified cosmic Chaplygin gas which has viscosity. We use exponential function method to solve non-linear equation and obtain time-dependent dark energy density. Then discuss Hubble expansion parameter and scale…

General Relativity and Quantum Cosmology · Physics 2013-06-05 Behnam Pourhassan

Yes, but only for a parameter value that makes it almost coincide with the standard model. We reconsider the cosmological dynamics of a generalized Chaplygin gas (gCg) which is split into a cold dark matter (CDM) part and a dark energy (DE)…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-03 R. F. vom Marttens , L. Casarini , W. Zimdahl , W. S. Hipólito-Ricaldi , D. F. Mota

In this paper, we perform a global constraint on the Ricci dark energy model with both the flat case and the non-flat case, using the Markov Chain Monte Carlo (MCMC) method and the combined observational data from the cluster X-ray gas mass…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Lixin Xu , Yuting Wang

In this note two cosmological models representing the flat Friedmann Universe filled with a Chaplygin fluid, with or without dust, are analyzed in terms of the recently proposed "statefinder" parameters. Trajectories of both models in the…

Astrophysics · Physics 2009-11-07 Vittorio Gorini , Alexander Kamenshchik , Ugo Moschella

This research paper deals with a transit dark energy cosmological model in $f(R, L_{m})$-gravity with observational constraints. For this, we consider a flat FLRW space-time and have taken a cosmological cosntant-like parameter $\beta$ in…

General Relativity and Quantum Cosmology · Physics 2023-05-03 Anirudh Pradhan , Dinesh Chandra Maurya , Gopikant K. Goswami , Aroonkumar Beesham

For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter $H(z)$ depending on…

General Relativity and Quantum Cosmology · Physics 2014-11-06 G. S. Sharov , E. G. Vorontsova

In the framework of spatially averaged inhomogeneous cosmologies in classical general relativity, effective Einstein equations govern the dynamics of averaged scalar variables in a scale--dependent way. A particular cosmology may be…

General Relativity and Quantum Cosmology · Physics 2010-08-23 Xavier Roy , Thomas Buchert

We investigate a spatially flat FLRW cosmological model in the framework of modified gravity described by the function \( f(R, L_m) = \alpha R + L_m^\beta + \gamma \), where \( L_m \) is the matter Lagrangian density. The modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2026-02-05 G. K. Goswami , Anirudh Pradhan , Syamala Krishnannair

Motivated by some previous works of Rudra et al we set to explore the background dynamics when dark energy in the form of New Variable Modified Chaplygin gas is coupled to dark matter with a suitable interaction in the universe described by…

General Physics · Physics 2015-06-15 Prabir Rudra , Chayan Ranjit , Sujata Kundu

We model the cosmological substratum by a viscous fluid that is supposed to provide a unified description of the dark sector and pressureless baryonic matter. In the homogeneous and isotropic background the \textit{total} energy density of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 W Zimdahl , W S Hipólito-Ricaldi , H E S Velten

On going good number of research works establish Modified Chaplygin Gas as one one of the most favoured candidates of Dark Energy. In our present work, new bound on the parameter space of associated model - parameter has been worked out…

General Physics · Physics 2010-06-09 Balendra Kr. Dev Choudhury , Julie Saikia

We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-12 Yun Chen , Bharat Ratra

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

We study the Generalized Chaplygin gas model (GCGM) using Gamma-ray bursts as cosmological probes. In order to avoid the so-called circularity problem we use cosmology-independent data set and Bayesian statistics to impose constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-19 R. C. Freitas , S. V. B. Gonçalves , H. E. S. Velten
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