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The generalized Chaplygin gas (GCG) model is the prototype of a unified model of dark energy (DE) and dark matter (DM). It is characterized by equation-of-state (EoS) parameters $A$ and $\alpha$. We use a statistical analysis of the 2dFGRS…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-22 J. C. Fabris , H. E. S. Velten , W. Zimdahl

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 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 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

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

We use different combinations of data samples to investigate the new generalized Chaplygin gas (NGCG) model in the context of dark energy (DE) cosmology. Using the available cosmological data, we put constraints on the the free parameters…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Fataneh Salahedin , Reza Pazhouhesh , Mohammad Malekjani

A decomposed generalised Chaplygin gas (gCg) with energy flux from dark energy to dark matter, represented by a negative value for the gas parameter $\alpha$, is shown to alleviate the tension between EDGES data and the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-10 C. Pigozzo , S. Carneiro , J. C. Fabris

In this paper, we use the latest observations of quasars covering the redshift range of $0.04<z<5.1$ to investigate a series of Chaplygin gas models as candidates for unified dark matter and dark energy. Based on different combinations of…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-15 Jie Zheng , Shuo Cao , Yujie Lian , Tonghua Liu , Yuting Liu , Zong-Hong Zhu

In this paper, we revisit generalized Chaplygin gas (GCG) model as a unified dark matter and dark energy model. The energy density of GCG model is given as $\rho_{GCG}/\rho_{GCG0}=[B_{s}+(1-B_{s})a^{-3(1+\alpha)}]^{1/(1+\alpha)}$, where…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Lixin Xu , Jianbo Lu , Yuting Wang

We propose in this paper a new model for describing the unification of dark energy and dark matter. This new model is a further generalization of the generalized Chaplygin gas (GCG) model, thus dubbed new generalized Chaplygin gas (NGCG)…

Astrophysics · Physics 2009-11-10 Xin Zhang , Feng-Quan Wu , Jingfei Zhang

The growth of large scale structure is studied in a universe containing both cold dark matter (CDM) and generalized Chaplygin gas (GCg). GCg is assumed to contribute only to the background evolution of the universe while the CDM component…

Astrophysics · Physics 2009-11-10 T. Multamaki , M. Manera , E. Gaztanaga

The Modified Chaplygin Gas (MCG) model belongs to the class of a unified models of dark energy (DE) and dark matter (DM). It is characterized by an equation of state (EoS) $p_c = B\rho - A/\rho^{\alpha}$, where the case $B=0$ corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 J. C. Fabris , C. Ogouyandjou , J. Tossa , H. E. S. Velten

The nature of the dark components (dark matter and dark energy) that dominate the current cosmic evolution is a completely open question at present. In reality, we do not even know if they really constitute two separated substances. In this…

Astrophysics · Physics 2009-11-10 Abha Dev , Deepak Jain , J. S. Alcaniz

We use the Markov Chain Monte Carlo method to investigate a global constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Constitution dataset of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 Lixin Xu , Jianbo Lu

A new diagnostic method, $Om$ is applied to generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy. On the basis of the recently observed data: the Union supernovae, the observational Hubble data, the SDSS…

Astrophysics · Physics 2010-11-02 Jianbo Lu , Lixin Xu

The generalized Chaplygin gas cosmology provides a prime example for the class of unified dark matter models, which substitute the two dark components of the standard cosmological LCDM concordance model by a single dark component. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-28 Ralf Aurich , Sven Lustig

The so called Generalized Chaplygin Gas (GCG) with the equation of state $p = - \frac{A}{{\rho}^{\alpha}}$ was recently proposed as a candidate for dark energy in the Universe. In this paper we confront the GCG with SNIa data. Specifically…

Astrophysics · Physics 2009-11-10 Marek Biesiada , Wlodzimierz Godlowski , Marek Szydlowski

We study Modified Chaplygin Gas (MCG) as a candidate for dark energy and predict the values of parameters of the gas for a physically viable cosmological model. The equation of state of MCG ($p=B \rho - \frac {A}{\rho^\alpha} $) involves…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-27 P. Thakur , S. Ghose , B. C. Paul

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

Although various cosmological observations congruously suggest that our universe is dominated by two dark components, the cold dark matter without pressure and the dark energy with negative pressure, the nature and origin of these…

Astrophysics · Physics 2009-11-10 Zong-Hong Zhu
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