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Related papers: Modified Chaplygin Gas with Variable G and $\Lambd…

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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

Explanations to the accelerated expansion of the Universe are usually sought either in modifications of Einstein gravity or in new forms of energy density. An example of modified gravity is the braneworld Dvali-Gabadadze-Porrati (DGP) model…

Astrophysics · Physics 2008-04-22 Matts Roos

In this paper, we consider three different models of dark energy in higher dimensional space-time and discuss about some cosmological parameters numerically. The first model is a single component universe including viscous varying modified…

General Relativity and Quantum Cosmology · Physics 2014-06-13 M. Khurshudyan , J. Sadeghi , M. Hakobyan , H. Farahani , R. Myrzakulov

We propose in this paper a new model for describing the unification of dark energy and dark matter. This new model is a further generalization of the generalized Chaplygin gas (GCG) model, thus dubbed new generalized Chaplygin gas (NGCG)…

Astrophysics · Physics 2009-11-10 Xin Zhang , Feng-Quan Wu , Jingfei Zhang

We develop an action principle to construct the dynamics that give rise to a minimal generalization of Einstein's equations, where the speed of light ($c$), the gravitational constant ($G$) and the cosmological constant ($\Lambda$) are…

General Relativity and Quantum Cosmology · Physics 2019-06-12 Renato Costa , Rodrigo R. Cuzinatto , Elisa. M. G. Ferreira , Guilherme Franzmann

We consider a scenario where the strong coupling constant was changing in the early universe. We attribute this change to a variation in the colour charge within a Bekenstein-like model. Treating the vacuum gluon condensate $<G^2>$ as a…

Astrophysics · Physics 2007-05-23 N. Chamoun , S. J. Landau , H. Vucetich

In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by brane cosmology. Here DGP and the RSII brane models have been considered separately.…

General Relativity and Quantum Cosmology · Physics 2012-03-12 Prabir Rudra , Ujjal Debnath , Ritabrata Biswas

The generalized Chaplygin gas is characterized by the equation of state p = - A/rho^alpha, with alpha > -1 and w > -1. We generalize this model to allow for the cases where alpha < -1 or w < -1. This generalization leads to three new…

Astrophysics · Physics 2013-05-29 A. A. Sen , Robert J. Scherrer

A linear cosmological perturbation theory of an almost homogeneous and isotropic perfect fluid Universe with dynamically evolving Newton constant $G$ and cosmological constant $\Lambda$ is presented. A gauge-invariant formalism is developed…

Astrophysics · Physics 2014-10-13 A. Bonanno , M. Reuter

A warm intermediate inflationary model in the context of Generalized Chaplygin Gas is investigated. We study this model in the weak and strong dissipative regimes, considering a generalized form of the dissipative coefficient…

General Relativity and Quantum Cosmology · Physics 2016-02-17 Ramón Herrera , Nelson Videla , Marco Olivares

In this paper, we have studied flat Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) model with modified Chaplygin gas (MCG) having equation of state $p_{m}=A\rho -% \frac{B}{\rho ^{\gamma }}$, where $0\leq A\leq 1$, $0\leq \gamma \leq 1$…

General Relativity and Quantum Cosmology · Physics 2022-07-20 J. K. Singh , Ritika Nagpal , S. K. J. Pacif

We suggest a perturbative approach for generic choices for the universe equation of state and introduce a novel framework for studying mass varying neutrinos (MaVaN's) coupled to the dark sector. For concreteness, we examine the coupling…

Astrophysics · Physics 2010-01-16 Alex E. Bernardini , O. Bertolami

We consider a double polytropic cosmological fluid and demonstrate that, when one constituent resembles a bare cosmological constant while the other emulates a generalized Chaplygin gas, a good description of the Universe's large-scale…

General Relativity and Quantum Cosmology · Physics 2024-03-27 Peter K. S. Dunsby , Orlando Luongo , Marco Muccino , Vineshree Pillay

We have explored the possibility of the co-existence of two forms of dark energy in the form of an alternative Generalized Chaplygin Gas (GCG) along with a scalar field of field theoretic or extra dimensional origin in the background of a…

General Relativity and Quantum Cosmology · Physics 2026-01-28 Mahasweta Biswas , Rikpratik Sengupta , Ujjal Debnath

Cosmologies with a Chaplygin gas have recently been explored with the objective of explaining the transition from a dust dominated epoch towards an accelerating expansion stage. We consider the hypothesis that the transition to the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Mariam Bouhmadi-Lopez , Paulo Vargas Moniz

We investigate the background dynamics when dark energy is coupled to dark matter in the universe described by loop quantum cosmology. We consider dark energy of the form modified Chaplygin gas. The dynamical system of equations is solved…

General Physics · Physics 2011-04-04 Mubasher Jamil , Ujjal Debnath

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

We explore the implications of type Ia supernovae (SNIa) observations on flat cosmological models whose matter content is an exotic fluid with equation of state, p=-M^(4(a+1))/rho^a. In this scenario, a single fluid component may drive the…

Astrophysics · Physics 2016-08-30 Martin Makler , Sergio Quinet de Oliveira , Ioav Waga

In this paper we study a model of modified gravity with non-minimal coupling between a general function of the Gauss-Bonnet invariant, $f(G)$, and matter Lagrangian from the point of view of the energy conditions. Such model has been…

General Physics · Physics 2015-06-03 A. Banijamali , B. Fazlpour , M. R. Setare

In this paper we consider Tachyonic scalar field as dark energy with interaction between components in the case of variable $G$ and $\Lambda$. We assume a flat Universe with specific form of scale factor and study cosmological parameters…

General Relativity and Quantum Cosmology · Physics 2015-02-03 J. Sadeghi , M. Khurshudyan , M. Hakobyan , H. Farahani