English
Related papers

Related papers: Variable Chaplygin Gas: Constraints from CMBR and …

200 papers

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 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 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

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

Accelerating Chaplygin gas combined with the decelerating braneworld Dvali-Gabadadze-Porrati (DGP) model can produce an overall accelerated expansion of the order of magnitude seen. Both models have similar asymptotic properties at early…

Astrophysics · Physics 2008-12-18 Matts Roos

A new class of accelerating cosmological models driven by a one-parameter version of the general Chaplygin-type equation of state is proposed. The simplified version is naturally obtained from causality considerations with basis on the…

Astrophysics · Physics 2010-11-05 J. A. S. Lima , J. V. Cunha , J. S. Alcaniz

We investigate the evolution of a FRW model fuelled by a modified Chaplygin gas with an equation of state $p = A\rho -\frac{B}{\rho^\alpha}$. An attempt is made here to constrain the free parameters of MCG model through the wellknown…

General Relativity and Quantum Cosmology · Physics 2015-10-23 D. Panigrahi , B. C. Paul , S. Chatterjee

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

The class of Chaplygin gas models regarded as a candidate of dark energy can be realized by a scalar field, which could drive the variation of the fine structure constant $\alpha$ during the cosmic time. This phenomenon has been observed…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-12 Chao-Jun Feng , Xin-Zhou Li

The generalized Chaplygin gas (GCG), is studied in this paper by using the latest observational data including 182 gold sample type Ia supernovae (Sne Ia) data, the ESSENCE Sne Ia data, the distance ratio from $z=0.35$ to $z=1089$ (the…

Astrophysics · Physics 2009-11-10 Puxun Wu , Hongwei Yu

The standard model of cosmology is investigated using time dependent cosmological constant $\Lambda$ and Newton's gravitational constant $G$. The total energy content is described by the modified Chaplygin gas equation of state. It is found…

General Relativity and Quantum Cosmology · Physics 2009-03-12 Mubasher Jamil , Farook Rahaman , Mehedi Kalam

We examine observational constraints on the generalized Chaplygin gas (GCG) model for dark energy from the 9 Hubble parameter data points, the 115 SNLS Sne Ia data and the size of baryonic acoustic oscillation peak at redshift, $z=0.35$. At…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Puxun Wu , Hongwei Yu

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

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

Assuming the flat FRW universe in Einstein's gravity filled with New Variable Modified Chaplygin gas (NVMCG) dark energy and dark matter having negligible pressure. In this research work we analyze the viability on the basis of recent…

General Physics · Physics 2012-11-13 Jhumpa Bhadra , Ujjal Debnath

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

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 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 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

We investigate observational constraints on the generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy from the latest observational data: the Union SNe Ia data, the observational Hubble data, the SDSS…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Jianbo Lu , Yuanxing Gui , Lixin Xu