English
Related papers

Related papers: Geometrical Diagnostics for Generalized Chaplygin …

200 papers

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

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

Recent observations from type Ia Supernovae and from cosmic microwave background (CMB) anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the so-called dark energy constituent of…

General Relativity and Quantum Cosmology · Physics 2009-11-11 M. S. Santos , S. V. B. Gonçalves , J. C. Fabris , E. M. de Gouveia Dal Pino

Despite the interest in dark matter and dark energy, it has never been shown that they are in fact two separate substances. We provide the first strong evidence that they are separate by ruling out a broad class of so-called unified dark…

Astrophysics · Physics 2008-11-26 Havard Sandvik , Max Tegmark , Matias Zaldarriaga , Ioav Waga

In this Letter, a modified Chaplygin gas (MCG) model of unifying dark energy and dark matter with the exotic equation of state $p_{MCG}=B\rho_{MCG} -\frac A{\rho_{MCG}^\alpha}$ is constrained from recently observed data: the 182 Gold SNe…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 Jianbo Lu , Lixin Xu , Jiechao Li , Baorong Chang , Yuanxing Gui , Hongya Liu

Using various latest cosmological datasets including Type-Ia supernovae, cosmic microwave background radiation, baryon acoustic oscillations, and estimations of the Hubble parameter, we test some dark energy models with parameterized…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-28 Jing Yang , Xin-Yan Fan , Chao-Jun Feng , Xiang-Hua Zhai

The generalized Chaplygin gas model (GCGM) contains 5 free parameters, here, they are constrained through the type Ia supernovae data, i.e., the ``gold sample'' of 157 supernovae data. Negative and large positive values for $\alpha$ are…

Astrophysics · Physics 2009-12-30 R. Colistete , J. C. Fabris

We consider a universe filled by a modified generalized Chaplygin gas together with a pressureless dark matter component. We get a thermodynamical interpretation for the modified generalized Chaplygin gas confined to the apparent horizon of…

General Relativity and Quantum Cosmology · Physics 2016-05-18 H. Ebadi , H. Moradpour

An exotic dark component, named generalized Chaplygin gas (Cg) and parameterized by an equation of state $p = -A/\rho_{Cg}^{\alpha}$ where $A$ and $\alpha$ are arbitrary constants, is one of the possible candidates for dark energy as well…

Astrophysics · Physics 2009-11-10 J. S. Alcaniz , J. A. S. Lima

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

In this paper, we study two different models of dark energy based on Chaplygin gas equation of state. The first model is the variable modified Chaplygin gas while the second one is the extended Chaplygin gas. Both models are considered in…

General Relativity and Quantum Cosmology · Physics 2015-02-10 E. O. Kahya , M. Khurshudyan , B. Pourhassan , R. Myrzakulov , A. Pasqua

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

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 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

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

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

In this paper, we reexamine the generalized Chaplygin gas (GCG) cosmology with the sign-changeable interaction. The dynamical analysis show that there exists de-Sitter attractors in this model, which means that the late-time behaviors of…

General Relativity and Quantum Cosmology · Physics 2015-10-13 Ping Xi , Ping Li

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

Motivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 A. Hernández-Almada , Miguel A. García-Aspeitia , M. A. Rodrírgues-Meza , V. Motta

We investigate the possibility of constraining Chaplygin dark energy models with current Integrated Sachs Wolfe effect data. In the case of a flat universe we found that generalized Chaplygin gas models must have an energy density such that…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Tommaso Giannantonio , Alessandro Melchiorri
‹ Prev 1 3 4 5 6 7 10 Next ›