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Related papers: Variable G correction to statefinder parameters of…

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Geometrical diagnostic, involving the statefinder $\{r,s\}$ and $Om(x)$, is widely used to discriminate different dark energy models. We apply the statefinder $\{r,s\}$ and $Om(x)$ to purely kinetic k-essence dark energy model with…

General Relativity and Quantum Cosmology · Physics 2010-04-30 Xiang-Ting Gao , Rong-Jia Yang

The coming few years are likely to witness a dramatic increase in high quality Sn data as current surveys add more high redshift supernovae to their inventory and as newer and deeper supernova experiments become operational. Given the…

Astrophysics · Physics 2008-11-26 Ujjaini Alam , Varun Sahni , Tarun Deep Saini , A. A. Starobinsky

The consequences of taking the generalized Chaplygin gas as the dark energy constituent of the Universe on the gravitational waves are studied and the spectrum obtained from this model, for the flat case, is analyzed. Besides its importance…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. C. Fabris , S. V. B. Goncalves , M. S. dos Santos

In this letter we consider two different models of our present universe. We choose the models which are consisting different sets of two seperate fluids. The first one of each set tries to justify the late time acceleration and the second…

General Physics · Physics 2019-03-27 Promila Biswas , Ritabrata Biswas

The four observables associated with gravitational lensing of distant quasars by intervening galaxies: image splittings, relative amplifications, time delays, and optical depths, provide separate measures of the strength of the…

Astrophysics · Physics 2009-08-18 Lawrence Krauss , Martin White

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

We study a dynamic $\Lambda$ model with varying gravitational constant $G$ under the Kaluza-Klein cosmology. Physical features and the limitations of the present model have been explored and discussed. Solutions are found mostly in…

General Physics · Physics 2015-05-28 Utpal Mukhopadhyay , Ipsita Chakraborty , Saibal Ray , A. A. Usmani

In the present work, we perform a comparative study of different interacting dark energy (DE) models using the Statefinder diagnostics. In particular, 17 different forms of the energy transfer rate $Q$ between DE and dark matter (DM) were…

General Relativity and Quantum Cosmology · Physics 2023-10-09 Raul Carrasco , Angel Rincon , Joel Saavedra , Nelson Videla

We study the Energy Conditions in modified $f(G)$ gravity, with $G$ being the topological Gauss-Bonnet term. Then we use the cosmographic parameters to constrain the functional form of the gravitational action and investigate the…

General Relativity and Quantum Cosmology · Physics 2026-03-18 Francesco Bajardi

The expansion of the Universe is accelerating, as testified by observations of supernovae of type Ia as a function of redshift. Explanations are of two types: modifications of Einstein gravity or new forms of energy, coined dark energy.The…

Astrophysics · Physics 2007-05-23 Matts Roos

A new model of dark energy namely "ghost dark energy model" has recently been suggested to interpret the positive acceleration of cosmic expansion. The energy density of ghost dark energy is proportional to the hubble parameter. In this…

General Relativity and Quantum Cosmology · Physics 2015-06-04 M. Malekjani , A. Khodam-Mohammadi

In this paper, we propose extended Chaplygin gas equation of state for which it recovers barotropic fluid with quadratic equation of state. We use numerical method to investigate the behavior of some cosmological parameters such as scale…

General Relativity and Quantum Cosmology · Physics 2014-09-17 B. Pourhassan , E. O. Kahya

Viscous GCG(generalized Chaplygin gas) cosmology is discussed, assuming that there is bulk viscosity in the barotropic fluid and GCG. The dynamical analysis indicates that the phase…

Astrophysics · Physics 2009-11-11 Xiang-hua Zhai , You-dong Xu , Xin-zhou Li

We consider a holographic dark energy model, with a varying parameter, n, which evolves slowly with time. We obtain the differential equation describing evolution of the dark energy density parameter, $\Omega_d$, for the flat and non-flat…

General Relativity and Quantum Cosmology · Physics 2015-01-28 Bushra Majeed , Mubasher Jamil , Azad A. Siddiqui

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

In this work we explore 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. Dark…

General Physics · Physics 2015-06-05 Prabir Rudra

We study the correspondence between field theoretic and holographic dark energy density of the universe with the modified Chaplygin gas (MCG) respectively both in a flat and non-flat FRW universe. We present an equivalent representation of…

High Energy Physics - Theory · Physics 2008-09-23 B. C. Paul , P. Thakur , A. Saha

This paper explores the possibility of treating the exotic Chaplygin-gas (CG) fluid model as some manifestation of an $f(T)$ gravitation. To this end, we use the different cosmological CG equations of state, compare them with the equation…

General Relativity and Quantum Cosmology · Physics 2019-10-02 Shambel Sahlu , Joseph Ntahompagaze , Maye Elmardi , Amare Abebe

We present a scalar-field formulation of the generalized Chaplygin gas (GCG) and modified Chaplygin gas (MCG) models, in which the cosmic fluid dynamics are reproduced by canonical Lagrangians with analytically derived energy density…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 Yi-Syuan Wu , Chuan-Jui Li , W. F. Kao

In this letter, we have considered that the universe is filled with normal matter and variable modified Chaplygin gas. Also we have considered the interaction between normal matter and variable modified Chaplygin gas in FRW universe. Then…

General Relativity and Quantum Cosmology · Physics 2009-03-12 Surajit Chattopadhyay , Ujjal Debnath