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Related papers: GCG Parametrization for Growth Function and Curren…

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We place tight constraints on the growth index $\gamma$ by using the recent growth history results of 2dFGRS, SDSS-LRG, VIMOS-VLT deep Survey (VVDS) and {\em WiggleZ} datasets. In particular, we investigate several parametrizations of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Spyros Basilakos , Athina Pouri

In this study, we build upon the findings of Del Popolo et al. (2013) by further analyzing the influence of dynamical friction on the evolution of cosmological perturbations within the framework of the spherical collapse model (SCM) in a…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-11 A. Del Popolo , Saeed Fakhry , Maryam Shiravand , Morgan Le Delliou

We investigate the evolution of cosmic structures within the framework of modified gravity, specifically focusing on theories described by the function $f(R, L_m)$, where $R$ is the Ricci scalar and $L_m$ is the matter Lagrangian. This…

General Relativity and Quantum Cosmology · Physics 2025-07-08 G. K. Goswami , J. P. Saini

We have assumed the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter and the Generalized Cosmic Chaplygin gas (GCCG) type dark energy where dark matter follows the linear equation of state. We present the…

General Physics · Physics 2014-09-25 Chayan Ranjit , Ujjal Debnath

This paper investigates the accelerated cosmic expansion in the late Universe by examining two dark energy models, viscous modified Chaplygin gas (VsMCG) and variable modified Chaplygin gas (VMCG), within loop quantum cosmology alongside…

General Relativity and Quantum Cosmology · Physics 2024-08-12 Rownak Kundu , Ujjal Debnath , Himanshu Chaudhary , G. Mustafa

In this study, we investigate two dark energy models, MCJG and MCAG, in the context of $f(T)$ gravity within a non-flat FLRW Universe. Our analysis considers radiation, dark matter, and dark energy components. We compare the equation of…

General Relativity and Quantum Cosmology · Physics 2024-01-24 Himanshu Chaudhary , Ujjal Debnath , Tanusree Roy , Sayani Maity , G. Mustafa , Monika Arora

A single parameter, the gravitational growth index \gamma, succeeds in characterizing the growth of density perturbations in the linear regime separately from the effects of the cosmic expansion. The parameter is restricted to a very narrow…

Astrophysics · Physics 2010-11-05 Eric V. Linder , Robert N. Cahn

Reconstructing the expansion history of the Universe from type Ia supernovae data, we fit the growth rate measurements and put model-independent constraints on some key cosmological parameters, namely, $\Omega_\mathrm{m},\gamma$, and…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-10 Benjamin L'Huillier , Arman Shafieloo , Hyungjin Kim

The large-scale structure of the Universe and its evolution over time contains an abundance of cosmological information. One way to unlock this is by measuring the density and momentum power spectrum from the positions and peculiar…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-03 Fei Qin , Cullan Howlett , David Parkinson

We present a new model for the cross-covariance between galaxy redshift-space distortions and peculiar velocities. We combine this with the auto-covariance models of both probes in a fully self-consistent, maximum-likelihood method,…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-15 Caitlin Adams , Chris Blake

We exploit the gauge-invariant formalism to analyse the perturbative behaviour of two cosmological models based on the generalized Chaplygin gas describing both dark matter and dark energy in the present Universe. In the first model we…

Astrophysics · Physics 2009-06-23 V. Gorini , A. Y. Kamenshchik , U. Moschella , O. F. Piattella , A. A. Starobinsky

One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single `quartessential' fluid. Following such idea, this work presents a study of the evolution of perturbations of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sandro Silva e Costa , Maximiliano Ujevic , Alesandro Ferreira dos Santos

We study the late-time evolution of the Universe where dark energy (DE) is parametrized by a modified generalized Chaplygin gas (mGCG) on top of cold dark matter (CDM). We also take into account the radiation content of the Universe. In…

General Relativity and Quantum Cosmology · Physics 2015-12-22 Mariam Bouhmadi-López , Maxim Brilenkov , Ruslan Brilenkov , João Morais , Alexander Zhuk

We model the expansion history of the Universe as a Gaussian Process and find constraints on the dark energy density and its low-redshift evolution using distances inferred from the Luminous Red Galaxy (LRG) and Lyman-alpha (Ly$\alpha$)…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-06 Shahab Joudaki , Manoj Kaplinghat , Ryan Keeley , David Kirkby

A new diagnostic method, $Om$ is applied to generalized Chaplygin gas (GCG) model as the unification of dark matter and dark energy. On the basis of the recently observed data: the Union supernovae, the observational Hubble data, the SDSS…

Astrophysics · Physics 2010-11-02 Jianbo Lu , Lixin Xu

Motivated by recent developments in particle physics and cosmology, there has been growing interest in an unified description of dark matter and dark energy scenarios. In this paper we explore observational constraints from age estimates of…

Astrophysics · Physics 2011-06-21 J. S. Alcaniz , Deepak Jain , Abha Dev

Three decades ago Heath found the integral form of the exact analytic growing mode solution of the linear density perturbation $\delta$ on sub-horizon scales including the cosmological constant or the curvature term. Recently, we obtained…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-30 Seokcheon Lee , Kin-Wang Ng

In this paper we study the evolution of the FRW universe filled with variable modified Chaplygin gas (VMCG). We begin with a thermodynamical treatment of VMCG described by the equation of state $P = A\rho-B\rho^{-\alpha}$, and obtain its…

General Relativity and Quantum Cosmology · Physics 2025-08-11 Samarjit Chakraborty , Sarbari Guha , D. Panigrahi

Accelerating Chaplygin gas combined with the decelerating braneworld Dvali-Gabadadze-Porrati (DGP) model can produce an overall accelerated expansion of the order of magnitude seen. Both models have similar asymptotic properties at early…

Astrophysics · Physics 2008-12-18 Matts Roos

We will extend the study of the new generalized Chaplygin gas (NGCG) based on [JCAP 0601(2006)003]. Concretely, we will not only discuss the change rates of the energy densities and the energy transfer of this model, but also perform the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Wang Jun , Wu Ya-Bo , Wang Di , Yang Wei-Qiang