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We use the hybrid model of bulk viscosity and generalized chaplygin gas (GCG), named the viscous generalized chaplygin gas (VGCG) model, which is thought to be an alternate dark fluid of the universe. We explore the dynamics of the VGCG…

General Relativity and Quantum Cosmology · Physics 2023-03-13 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo

Spherically symmetric dark energy structures are investigated in the framework of a generalized Chaplygin gas (GCG), which has an equation of state of the form $P = - A/\rho^{\alpha}} $. We also study these in a modified GCG equation of…

General Relativity and Quantum Cosmology · Physics 2007-06-07 Abiy G. Tekola

I review the theoretical motivation for varying fundamental couplings and discuss how these measurements can be used to constrain a number of fundamental physics scenarios that would otherwise be inacessible to experiment. As a case study I…

Astrophysics · Physics 2015-06-24 C. J. A. P. Martins

The possibility that the dark energy may be described by the Chaplygin gas is discussed. Some observational constraints are established. These observational constraints indicate that a unified model for dark energy and dark matter through…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. Colistete , J. C. Fabris , S. V. B. Goncalves , P. E. de Souza

Unification of dark matter and dark energy as short- and long-range manifestations of a single cosmological substance is possible in models described by the generalized Chaplygin gas equation of state. We show it admits halo-like structures…

General Relativity and Quantum Cosmology · Physics 2017-12-20 T. de Beer , J. W. van Holten

Holographic dark energy (HDE), presents a dynamical view of dark energy which is consistent with the observational data and has a solid theoretical background. Its definition follows from the entropy-area relation $S(A)$, where $S$ and $A$…

General Relativity and Quantum Cosmology · Physics 2014-11-20 M. Umar Farooq , Muneer A. Rashid , Mubasher Jamil

The cosmic time dependencies of $G$, $\alpha$, $\hbar$ and of Standard Model parameters like the Higgs vev and elementary particle masses are studied in the framework of a new dark energy interpretation. Due to the associated time variation…

High Energy Physics - Phenomenology · Physics 2025-11-27 Bodo Lampe

We study the linear growth function $f$ for large scale structures in a cosmological scenario where Generalised Chaplygin Gas (GCG) serves as dark energy candidate. We parametrize the growth index parameter as a function of redshift and do…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Gaveshna Gupta , Somasri Sen , Anjan A. Sen

The interacting polytropic gas dark energy model is investigated from the viewpoint of statefinder diagnostic tool and $w-w^{\prime}$ analysis. The dependency of the statefinder parameters on the parameter of the model as well as the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 M. Malekjani , A. Khodam-Mohammadi

We investigate the cosmological constraints on the Variable Chaplygin gas model from the latest observational data: SCP Union 2.1 compilation dataset of Type Ia supernovae (SNe Ia), Pantheon sample of SNe Ia, Platinum Sample of Gamma Ray…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-11 Ashley Chraya , Yuvraj Muralichandran , Geetanjali Sethi

We formulate a Zel'dovich-like approximation for the Chaplygin gas equation of state P = -A/rho, and sketch how this model unifies dark matter with dark energy in a geometric setting reminiscent of M-theory.

Astrophysics · Physics 2007-05-23 Neven Bilic , Gary B. Tupper , Raoul D. Viollier

We consider a model of the Universe with variable G and {\Lambda}. Subject of our interest is a phenomenological model for {\Lambda} proposed and considered in this article first time (up to our knowledge). Modification based on an…

General Relativity and Quantum Cosmology · Physics 2015-01-13 M. Khurshudyan , J. Sadeghi , E. Chubaryan , H. Farahani

In this work, we investigate Newtonian cosmologies with a time-varying gravitational constant, $G(t)$. We examine whether such models can reproduce the low-redshift cosmological observations without a cosmological constant, or any other…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-01 Ekim Taylan Hanımeli , Isaac Tutusaus , Brahim Lamine , Alain Blanchard

Modified gravity theories with the Gauss-Bonnet term $G=R^2-4R^{\mu\nu}R_{\mu\nu}+R^{\mu\nu\rho\sigma}R_{\mu\nu\rho\sigma}$ have recently gained a lot of attention as a possible explanation of dark energy. We perform a thorough phase space…

General Relativity and Quantum Cosmology · Physics 2010-10-01 Shuang-Yong Zhou , Edmund J. Copeland , Paul M. Saffin

Nearly all proposed tests for the nature of dark energy measure some combination of four fundamental observables: the Hubble parameter H(z), the distance-redshift relation d(z), the age-redshift relation t(z), or the linear growth factor…

Astrophysics · Physics 2009-11-13 David H. Weinberg

In considering alternative higher-order gravity theories, one is liable to be motivated in pursuing models consistent and inspired by several candidates of a fundamental theory of quantum gravity. Indeed, motivations from string/M-theory…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Nadiezhda Montelongo García , Tiberiu Harko , Francisco S. N. Lobo , José P. Mimoso

In this work, we have extended the analysis on the generalized Chaplygin gas (GCG) model as the unification of dark energy and dark matter. Specifically, we have shown that the model of our consideration known as the new generalized…

General Relativity and Quantum Cosmology · Physics 2022-04-13 Abdulla Al Mamon , Andronikos Paliathanasis , Subhajit Saha

We examine observational constraints on the generalized Chaplygin gas (GCG) model for dark energy from the 9 Hubble parameter data points, the 115 SNLS Sne Ia data and the size of baryonic acoustic oscillation peak at redshift, $z=0.35$. At…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Puxun Wu , Hongwei Yu

Neutrinos coupled to an underlying scalar field in the scenario for unification of mass varying dark matter and cosmon-{\em like} dark energy is examined. In the presence of a tiny component of mass varying neutrinos, the conditions for the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-15 Alex E. Bernardini

Observational evidence for the existence of dark energy is strong. Here we suggest a model which is based on a modified gravitational theory in 5D and interpret the 5th dimension as a manifestation of dark energy in the 4D observable…

High Energy Physics - Theory · Physics 2008-01-22 H. Alavirad , N. Riazi
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