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Related papers: Generalized Chaplygin Gas in a modified gravity ap…

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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

This study explores the link between Modified Gravity and modifications of phase space volume. Analyzing Fermi gas modifications {in the non-relativistic limit of the} Ricci-based gravities, we derive a generalized partition function in the…

General Relativity and Quantum Cosmology · Physics 2024-01-10 Aneta Wojnar

In this paper, we have considered new modified Chaplygin gas (NMCG) model which interpolates between radiation at early stage and $\Lambda$CDM at late stage. This model is regarded as a unification of dark energy and dark matter (with…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Surajit Chattopadhyay , Ujjal Debnath

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

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

We use the Markov Chain Monte Carlo method to investigate a global constraints on the modified Chaplygin gas (MCG) model as the unification of dark matter and dark energy from the latest observational data: the Union2 dataset of type…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Jianbo Lu , Lixin Xu , Yabo Wu , Molin Liu

In the theories of generalized modified gravity, the acceleration equation is generally fourth order. So it is hard to analyze the evolution of the Universe. In this paper, we present a class of generalized modified gravity theories which…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Changjun Gao

We study new FRW type cosmological models of modified gravity treated on the background of Palatini approach. These models are generalization of Einstein gravity by the presence of a scalar field non-minimally coupled to the curvature. The…

General Relativity and Quantum Cosmology · Physics 2012-03-13 A. Borowiec , M. Kamionka , A. Kurek , M. Szydlowski

Introducing a fundamental constant of nature with dimensions of acceleration into the theory of gravity makes it possible to extend gravity in a very consistent manner. At the non-relativistic level a MOND-like theory with a modification in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 D. A. Carranza , S. Mendoza , L. A. Torres

Despite the remarkable success of the standard LambdaCDM model in describing the evolution of the universe, several unresolved issues remain, such as the true nature of dark energy, fine-tuning problems, and the persistent Hubble tension.…

General Relativity and Quantum Cosmology · Physics 2025-09-15 Mahendra Goray , Bijan Saha

We have assumed the FRW model of the universe in Galileon gravity, which is filled with dark matter and Modified Chaplygin gas (MCG) type dark energy. We present the Hubble parameter in terms of some unknown parameters and observational…

General Physics · Physics 2015-06-19 Chayan Ranjit , Prabir Rudra , Ujjal Debnath

In this work the modified Chaplygin gas is related to a cosmological scalar field. Analytical results, more general than the solutions previously shown in the literature, are presented for the case when the curvature is absent, and one…

General Relativity and Quantum Cosmology · Physics 2008-03-03 Sandro Silva e Costa

In our companion paper we identified a complete set of manifestly gauge-invariant observables for general relativity. This was possible by coupling the system of gravity and matter to pressureless dust which plays the role of a dynamically…

General Relativity and Quantum Cosmology · Physics 2010-02-17 K. Giesel , S. Hofmann , T. Thiemann , O. Winkler

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger , Phillip Zukin

We apply methods of dynamical systems to study the behaviour of universe dominated by the generalized Chaplygin gas. We reduce the dynamics to a 2-dimensional Hamiltonian system and study its behaviour for various ranges of parameters. The…

Astrophysics · Physics 2009-11-10 Marek Szydlowski , Wojciech Czaja

We study the growth of subhorizon perturbations in brane-induced gravity using perturbation theory. We solve for the linear evolution of perturbations taking advantage of the symmetry under gauge transformations along the extra-dimension to…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-10 Roman Scoccimarro

The observed accelerated expansion of the Universe may be explained by dark energy or the breakdown of general relativity (GR) on cosmological scales. When the latter case, a modified gravity scenario, is considered, it is often assumed…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-04 Jiro Matsumoto , Teppei Okumura , Misao Sasaki

In this paper, we have considered a model of modified Chaplygin gas in VSL theory with variable gravitational constant $G$. We have shown that the evolution of the universe starts from radiation era to phantom model. The whole evolution of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anup Kumar Singha , Ujjal Debnath

A reconstruction of modified gravity is proposed by establishing a correspondence between the effective density of the modified gravity and the holographic density. The non-homogeneous term in the modified Friedmann equation, generated by…

General Relativity and Quantum Cosmology · Physics 2019-02-20 L. N. Granda

Chern-Simons modified gravity is an effective extension of general relativity that captures leading-order, gravitational parity violation. Such an effective theory is motivated by anomaly cancelation in particle physics and string theory.…

High Energy Physics - Theory · Physics 2015-05-13 Stephon Alexander , Nicolas Yunes