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We study the linear growth function $f$ for large scale structures in a cosmological scenario where Generalised Chaplygin Gas (GCG) serves as dark energy candidate. We parametrize the growth index parameter as a function of redshift and do…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Gaveshna Gupta , Somasri Sen , Anjan A. Sen

We investigate the unification scenario provided by the generalised Chaplygin gas model (a perfect fluid characterized by an equation of state p = -A/\rho^{\alpha}). Our concerns lie with a possible tension existing between background…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Juliano Pereira Campos , Júlio César Fabris , Rafael Perez , Oliver F. Piattella , Hermano Velten

We make a comparison for ten typical, popular dark energy models according to their capabilities of fitting the current observational data. The observational data we use in this work include the JLA sample of type Ia supernovae observation,…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-08 Yue-Yao Xu , Xin Zhang

We study the nonlinear regime of Unified Dark Energy models, using Generalized Chaplygin Gas cosmologies as a representative example, and introduce a new parameter characterizing the level of small scale clustering in these scenarios. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 P. P. Avelino , K. Bolejko , G. F. Lewis

Any unified dark matter cosmology can be decomposed into dark matter interacting with vacuum energy, without introducing any additional degrees of freedom. We present observational constraints on an interacting vacuum plus dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-16 Yuting Wang , David Wands , Lixin Xu , Josue De-Santiago , Alireza Hojjati

The differential age data of astrophysical objects that have evolved passivelly during the history of the universe (e.g. red galaxies) allows to test theoretical cosmological models through the predicted Hubble function expressed in terms…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. C. Fabris , P. L. C. de Oliveira , H. E. S. Velten

This study examines accelerated cosmic expansion using the Viscous Modified Chaplygin Gas (VMMG) and Generalized Cosmic Chaplygin Gas (GCCM) within Horava-Lifshitz gravity. Our aim is to constrain essential cosmological parameters, such as…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-12 Sayani Maity , Himanshu Chaudhary , Ujjal Debnath , S. K. Maurya , G. Mustafa

In this paper, we study cosmologies containing the reduced modified Chaplygin gas (RMCG) fluid which is reduced from the modified Chaplygin gas $p=A\rho-B\rho^{-\alpha}$ for the value of $\alpha=-1/2$. In this special case, dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Jianbo Lu , Danhua Geng , Lixin Xu , Yabo Wu , Molin Liu

We model the cosmic medium as the mixture of a generalized Chaplygin gas and a pressureless matter component. Within a neo-Newtonian approach we compute the matter power spectrum. The 2dFGRS data are used to discriminate between unified…

Astrophysics · Physics 2015-05-13 J. C. Fabris , S. V. B. Goncalves , H. E. S. Velten , W. Zimdahl

The consequences of taking the generalized Chaplygin gas as the dark energy constituent of the Universe on the gravitational waves are studied and the spectrum obtained from this model, for the flat case, is analyzed. Besides its importance…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. C. Fabris , S. V. B. Goncalves , M. S. dos Santos

The correspondence of the Gauss-Bonnet (GB) and its modification (MGB) models of dark energy with the standard and generalized Chaplygin gas-scalar field models (SCG and GCG) have been studied in a {\deg}at universe. The exact solution of…

General Relativity and Quantum Cosmology · Physics 2016-11-10 A. Khodam-Mohammadi , E. Karimkhani , A. Alaei

We present a scalar-field formulation of the generalized Chaplygin gas (GCG) and modified Chaplygin gas (MCG) models, in which the cosmic fluid dynamics are reproduced by canonical Lagrangians with analytically derived energy density…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Yi-Syuan Wu , Chuan-Jui Li , W. F. Kao

We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 W. S. Hipólito-Ricaldi , H. E. S. Velten , W. Zimdahl

The supernova type Ia observational data are fitted using a model with cold dark matter and the Chaplygin gas. The Chaplygin gas, which is characterized by a negative pressure varying with the inverse of density, represents in this model…

Astrophysics · Physics 2007-05-23 J. C. Fabris , S. V. B. Goncalves , P. E. de Souza

We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble…

Astrophysics · Physics 2008-11-26 Puxun Wu , Hongwei Yu

The fact that Einstein's equations connect the space-time geometry to the total matter content of the cosmic substratum, but not to individual contributions of the matter species, can be translated into a degeneracy in the cosmological dark…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Rodrigo von Marttens , Dinorah Barbosa , Jailson Alcaniz

We study cosmological models with modified Chaplygin gas (in short, MCG) to determine observational constraints on its EoS parameters. The observational data of the background and the growth tests are employed. The background test data…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-02 Bikash Chandra Paul , Prasenjit Thakur , Aroonkumar Beesham

This paper investigates the accelerated cosmic expansion in the late Universe by examining two dark energy models, viscous modified Chaplygin gas (VsMCG) and variable modified Chaplygin gas (VMCG), within loop quantum cosmology alongside…

General Relativity and Quantum Cosmology · Physics 2024-08-12 Rownak Kundu , Ujjal Debnath , Himanshu Chaudhary , G. Mustafa

The generalized Chaplygin gas model represents an attempt to unify dark matter and dark energy. It is characterized by a fluid with an equation of state $p = - A/\rho^\alpha$. It can be obtained from a generalization of the DBI action for a…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 J. C. Fabris , T. C. C. Guio , M. Hamani Daouda , O. F. Piattella

Motivated by recent developments in particle physics and cosmology, there has been growing interest in an unified description of dark matter and dark energy scenarios. In this paper we explore observational constraints from age estimates of…

Astrophysics · Physics 2011-06-21 J. S. Alcaniz , Deepak Jain , Abha Dev
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