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Related papers: Horava-Lifshitz cosmology with generalized Chaplyg…

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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

The occurrence of a bounce in the FRW cosmology requires modifications of General Relativity. An example of such a modification is the recently proposed Horava-Lifshitz theory of gravity, which includes a "dark radiation" term with a…

High Energy Physics - Theory · Physics 2011-06-24 Ewa Czuchry

The occurrence of a bounce in FRW cosmology requires modifications of general relativity. An example of such a modification is the recently proposed Horava-Lifshitz theory of gravity, which includes a ``dark radiation'' term with a negative…

High Energy Physics - Theory · Physics 2011-03-31 Ewa Czuchry

In the framework of renormalization-group improved cosmologies, we analyze both theoretically and observationally the exact and general solution of the matter-dominated cosmological equations, using the expression of \Lambda = \Lambda(G)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Ester Piedipalumbo , Paolo Scudellaro , Giampiero Esposito , Claudio Rubano

Data from Type Ia supernovae, along with X-ray cluster estimates of the universal baryon fraction and Big Bang Nucleosynthesis (BBN) determinations of the baryon-to-photon ratio, are used to provide estimates of several global cosmological…

Astrophysics · Physics 2007-05-23 G. Steigman , T. P. Walker , A. Zentner

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

In this paper, we revisit generalized Chaplygin gas (GCG) model as a unified dark matter and dark energy model. The energy density of GCG model is given as $\rho_{GCG}/\rho_{GCG0}=[B_{s}+(1-B_{s})a^{-3(1+\alpha)}]^{1/(1+\alpha)}$, where…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Lixin Xu , Jianbo Lu , Yuting Wang

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

We present exact solutions of the gravitational field equations in the generalized Randall-Sundrum model for an anisotropic brane with Bianchi type I geometry, with a generalized Chaplygin gas as matter source. The generalized Chaplygin…

General Relativity and Quantum Cosmology · Physics 2009-11-11 M. K. Mak , T. Harko

A modified Chaplygin gas model (MCG), $\rho_{MCG}/\rho_{MCG0}=[B_{s}+(1-B_{s})a^{-3(1+B)(1+\alpha)}]^{1/(1+\alpha)}$, as a unified dark matter model and dark energy model is constrained by using current available cosmic observational data…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-26 Lixin Xu , Yuting Wang , Hyerim Noh

We find exact solution of the Einstein equations in the context of the brane world scenario. We have supposed a {generalized chaplygin gas} equation of state for bulk. This study display a constant energy density and pressure for bulk in…

General Relativity and Quantum Cosmology · Physics 2014-01-20 Kh. Saaidi , A. Mohammadi

In the current framework of Einstein's equations in general relativity (GR), gravity is described by the spacetime curvature. However, there are other descriptions where the origin of gravity can be understood through torsion and…

General Relativity and Quantum Cosmology · Physics 2022-12-02 Nakul Aggarwal , Ali Pourmand , Fatimah Shojai , Harish Parthasarathy

Tight constraints on cosmological parameters can be obtained with standard candles spanning a range of redshifts as large as possible. We propose to treat SN Ia and long Gamma-Ray Bursts (GRBs) as a single class of candles. Taking advantage…

Astrophysics · Physics 2007-05-23 C. Firmani , V. Avila-Reese , G. Ghisellini , G. Ghirlanda

Horava and Melby-Thompson recently proposed a new version of the Horava-Lifshitz theory of gravity, in which the spin-0 graviton is eliminated by introducing a Newtonian pre-potential $\phi$ and a local U(1) gauge field $A$. In this paper,…

High Energy Physics - Theory · Physics 2011-02-23 Anzhong Wang , Yumei Wu

This paper aims to study the use of future SNAP data together with the result of searches for strong gravitational lenses in future large quasar surveys to constrain the Generalized Chaplygin Gas (GCG) model. The GCG is considered as a…

Astrophysics · Physics 2009-11-07 P. T. Silva , O. Bertolami

Considering perturbation growth in spherical Top-Hat model of structure formation in a generalized Chaplygin gas dominated universe, we want to study this scenario with a modified Chaplygin gas model. The evolution of background and…

General Relativity and Quantum Cosmology · Physics 2015-05-11 S. Karbasi , H. Razmi

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics in a non-flat FRW universe containing the interacting generalized Chaplygin gas with the baryonic matter. The dynamical apparent horizon is…

General Physics · Physics 2011-04-20 K. Karami , S. Ghaffari , M. M. Soltanzadeh

We employ the generalized Chaplygin gas of interacting dark energy to obtain the equation of state for the generalized Chaplygin gas energy density in non-flat universe. By choosing a negative value for $B$ we see that $w_{\rm…

General Relativity and Quantum Cosmology · Physics 2010-10-27 M R Setare

We have considered the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter (perfect fluid with negligible pressure) and the modified Chaplygin gas (MCG) type dark energy. We present the Hubble parameter in terms…

General Physics · Physics 2015-06-05 Shuvendu Chakraborty , Ujjal Debnath , Chayan Ranjit