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Related papers: Generalized Chaplygin gas and CMBR constraints

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In this work, we have studied the observational constraints on the Cardassian Model for the dark energy. We have compared the model with existing Supernova data. The dependence of the location of the Cosmic Microwave Background Radiation…

Astrophysics · Physics 2009-11-07 S. Sen , A. A. Sen

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

In this paper, a modified Chaplygin gas model of unifying dark energy and dark matter with exotic equation of state $p=B\rho-\frac{A}{\rho^{\alpha}}$ which can also explain the recent accelerated expansion of the universe is investigated by…

Astrophysics · Physics 2008-11-26 Dao-jun Liu , Xin-zhou Li

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

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

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

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 generalized Chaplygin gas model is characterized by the equation of state $p = - \frac{A}{\rho^\alpha}$. It is generally stated that the case $\alpha = 0$ is equivalent to a model with cosmological constant and dust ($\Lambda CDM$). In…

Astrophysics · Physics 2009-11-10 J. C. Fabris , S. V. B. Gonçalves , R. de Sá Ribeiro

We derive constraints on the parameter space of the unified model of dark energy and dark matter, the Generalized Chaplygin Gas (GCG), from the amplitudes and positions of the first few peaks and first trough of the cosmic microwave…

Astrophysics · Physics 2008-11-26 T. Barreiro , O. Bertolami , P. Torres

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

Observational manifestations of accelerated expansion of the universe, in particular, recent data for Type Ia supernovae, baryon acoustic oscillations, for the Hubble parameter $H(z)$ and cosmic microwave background constraints are…

General Relativity and Quantum Cosmology · Physics 2016-08-02 G. S. Sharov

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

In this paper, we undertake a unified study of background dynamics and cosmological perturbations in the presence of the Chaplygin gas. This is done by first constraining the background cosmological parameters of different Chaplygin gas…

General Relativity and Quantum Cosmology · Physics 2023-10-12 Shambel Sahlu , Heba Sami , Renier Hough , Maye Elmardi , Anna-Mia Swart , Amare Abebe

The recent observational evidences for the present accelerated stage of the Universe have stimulated renewed interest for alternative cosmologies. In general, such models contain an unknown negative-pressure dark component that explains the…

Astrophysics · Physics 2009-11-07 J. V. Cunha , J. S. Alcaniz , J. A. S. Lima

We study the impact of a generalized Chaplygin gas as a candidate for dark energy on CMB anisotropies. The generalized Chaplygin gas is a fluid component with an exotic equation of state, $p = - A/\rho^\alpha$ (a polytropic gas with…

Astrophysics · Physics 2009-11-07 Daniela Carturan , Fabio Finelli

A modified Chaplygin gas model (MCG), $\rho_{MCG}/\rho_{MCG0}=[B_{s}+(1-B_{s})a^{-3(1+B)(1+\alpha)}]^{1/(1+\alpha)}$, as a unified dark matter model and dark energy model is constrained by using current available cosmic observational data…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-26 Lixin Xu , Yuting Wang , Hyerim Noh

We investigate observational constraints on the generalized Chaplygin gas (GCG) model including the gamma-ray bursts (GRBs) at high redshift obtained directly from the Union2 type Ia supernovae (SNe Ia) set. By using the Markov Chain Monte…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Nan Liang , Lixin Xu , Zong-Hong Zhu

We investigate cosmological constraints on the Variable Chaplygin gas model parameters with latest observational data of the Fast Radio Bursts and compare the results with previous constraints obtained using SNe Ia (Pantheon+SHOES), Gamma…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-25 Geetanjali Sethi , Udish Sharma , Nadia Makhijani

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

The generalized Chaplygin gas model with parameter space $\alpha>-1$ is studied in this paper. Some reasonable physical constraints are added to justify the use of the larger parameter space. The Type Ia supernova data and age data of some…

Astrophysics · Physics 2008-11-26 Yungui Gong
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