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Related papers: Observational Constraints on the Generalized Chapl…

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In this paper, we continue our previous work of studying viscous generalized Chaplygin gas (VGCG) as a unified dark fluid but including the bulk viscosity perturbation. By using the currently available cosmic observational data from SNLS3,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-03 Wei Li , Lixin Xu

In cosmology, the cosmic curvature $K$ and the cosmological constant $\Lambda$ are two important parameters, and the values have strong influence on the behavior of the universe. In the context of normal cosmology, under the ordinary…

General Relativity and Quantum Cosmology · Physics 2017-08-11 Ying-Qiu Gu

The generalized Chaplygin gas, characterized by the equation of state $p=-\mathcal{A}/\rho^{\alpha}$, has been considered as a model for dark energy due its dark-energy-like evolution at late times. When dissipative processes are taken…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Norman Cruz , Samuel Lepe , Francisco Pena

If the spatial section of the universe is multiply connected, repeated images or patterns are expected to be detected observationally. However, due to the finite distance to the last scattering surface, such pattern repetitions could be…

Astrophysics · Physics 2008-11-26 B. Mota , M. Makler , M. J. Reboucas

We study the implications on both background and perturbation evolution of introducing a Chaplygin gas component in the universe's ingredients. We perform likelihood analyses using wide-ranging, SN1a, CMB and large scale structure…

Astrophysics · Physics 2010-04-06 Rachel Bean , Olivier Doré

We study the cosmological scenario arising from the dynamics of a generalized Chaplygin gas. The equation of state of the system is given in terms of the energy density, $\rho$, and pressure, $p$, by the relationship $p = -…

Astrophysics · Physics 2007-05-23 M. C. Bento , O. Bertolami , A. A. Sen

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

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 the paper, we have presented a higher-dimensional cosmological model with a generalized Chaplygin-type gas to explain the recent acceleration of the universe. Dimensional reduction is feasible in this model, and our solutions are…

General Relativity and Quantum Cosmology · Physics 2025-07-01 D. Panigrahi , B. C. Paul , S. Chatterjee

We revisit the paradigm of unified dark energy discussing in detail the averaging problem in this type of scenarios, highlighting the need for a full non-linear treatment. We also address the question of if and how models with one or…

Astrophysics · Physics 2009-11-13 P. P. Avelino , L. M. G. beça , C. J. A. P. Martins

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 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

Different models of the cosmic substratum which pretend to describe the present stage of accelerated expansion of the Universe like the $\Lambda$CDM model or a Chaplygin gas, can be seen as special realizations of a holographic dark energy…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Winfried Zimdahl

In this paper, we present a unified scheme based on the fluid description of the dark sector of the universe. The scheme captures models with interaction between dark energy and dark matter, being the core of generalization the time-varying…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-20 W. J. C. da Silva , J. E. Gonzalez , R. Silva , J. S. Alcaniz

The generalized Chaplygin gas provides an interesting candidate for the present accelerated expansion of the universe. We explore a geometrical explanation for the generalized Chaplygin gas within the context of brane world theories where…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Heydari-Fard , H. R. Sepangi

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

Cosmological observations are normally fit under the assumption that the dark sector can be decomposed into dark matter and dark energy components. However, as long as the probes remain purely gravitational, there is no unique decomposition…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 Martin Kunz , Andrew R Liddle , David Parkinson , Changjun Gao

We examine the properties of dark energy and dark matter through the study of the variation of the electromagnetic coupling. For concreteness, we consider the unification model of dark energy and dark matter, the generalized Chaplygin gas…

Astrophysics · Physics 2008-11-26 M. C. Bento , O. Bertolami , P. Torres

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

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