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The evolution of a universe modelled as a mixture of generalised Chaplygin gas and ordinary matter field is studied for a Robertson Walker type of spacetime. This model could interpolate periods of a radiation dominated, matter dominated…

General Relativity and Quantum Cosmology · Physics 2017-02-14 D. Panigrahi , S. Chatterjee

Despite our present-day inability to predict the topology of the universe one may expect that we should be able to detect it in the near future, given the increasing accuracy in the astro-cosmological observations. Motivated by this, we…

Astrophysics · Physics 2007-05-23 M. Makler , B. Mota , M. J. Reboucas

We study the Generalized Chaplygin gas model (GCGM) using Gamma-ray bursts as cosmological probes. In order to avoid the so-called circularity problem we use cosmology-independent data set and Bayesian statistics to impose constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-19 R. C. Freitas , S. V. B. Gonçalves , H. E. S. Velten

The so called Generalized Chaplygin Gas (GCG) with the equation of state $p = - \frac{A}{{\rho}^{\alpha}}$ was recently proposed as a candidate for dark energy in the Universe. In this paper we confront the GCG with SNIa data. Specifically…

Astrophysics · Physics 2009-11-10 Marek Biesiada , Wlodzimierz Godlowski , Marek Szydlowski

Motivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 A. Hernández-Almada , Miguel A. García-Aspeitia , M. A. Rodrírgues-Meza , V. Motta

Recent observations from type Ia Supernovae and from cosmic microwave background (CMB) anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the so-called dark energy constituent of…

General Relativity and Quantum Cosmology · Physics 2009-11-11 M. S. Santos , S. V. B. Gonçalves , J. C. Fabris , E. M. de Gouveia Dal Pino

The mass power spectrum for a Universe dominated by the Chaplygin gas is evaluated numerically from scales of the order of the Hubble horizon to 100 Mpc. The results are compared with a pure baryonic Universe and a cosmological constant…

Astrophysics · Physics 2016-08-16 J. C. Fabris , S. V. B. Gonçalves , P. E. de Souza

In this paper we study the Chaplygin gas model as a candidate for inflation in the framework of the Randall Sundrum type-II braneworld model. We consider the original and generalized Chaplygin gas model in the presence of monomial…

General Relativity and Quantum Cosmology · Physics 2018-05-01 A. Safsafi , I. Khay , F. Salamate , H. Chakir , M. Bennai

We investigate the linear growth function for the large scale structures of the universe considering modified Chaplygin gas as dark energy. Taking into account observational growth data for a given range of redshift from the Wiggle-Z…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 B. C. Paul , P. Thakur

We show that the observed rotation curves of spiral galaxies constrain the sound speed of the dark matter to be $c_s < 10^{-4} c$, where $c$ is the speed of light in vacuum. Using the Modified Chaplygin Gas as a representative example of a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-06 P. P. Avelino , V. M. C. Ferreira

We extend the Chaplygin gas model for dark matter and dark energy unification by promoting the Chaplygin gas parameter A to the potential for an extra scalar with canonical kinetic energy. The hybrid model allows for accelerated Hubble…

Astrophysics · Physics 2009-11-10 Neven Bilic , Gary B. Tupper , Raoul D. Viollier

Hybrid Chaplygin gas model is put forward, in which the gases play the role of dark energy. For this model the coincidence problem is greatly alleviated. The effective equation of state of the dark energy may cross the phantom divide…

Astrophysics · Physics 2015-05-13 Hongsheng Zhang , Zong-Hong Zhu , Lihua Yang

We propose a new fluid model of dark energy for $-1 \leq \omega_{\text{eff}} \leq 0$ as an alternative to the generalized Chaplygin gas models. The energy density of dark energy fluid is severely suppressed during barotropic matter dominant…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-23 Hoavo Hova , Huanxiong Yang

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

In this work we have studied the possibility of obtaining cosmic acceleration in Brans-Dicke theory with varying or constant $\omega$ (Brans- Dicke parameter) and with or without self-interacting potential, the background fluid being…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Writambhara Chakraborty , Ujjal Debnath

We model the cosmological substratum by a viscous fluid that is supposed to provide a unified description of the dark sector and pressureless baryonic matter. In the homogeneous and isotropic background the \textit{total} energy density of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 W Zimdahl , W S Hipólito-Ricaldi , H E S Velten

We investigate the impact of the generalized uncertainty principle proposed by some approaches to quantum gravity such as string theory and doubly special relativity on the cosmology. Using generalized Poisson brackets, we obtain the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Mahdi Rashki , Majid Fathi , Behrang Mostaghel , Sahram Jalalzadeh

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

In this paper, we study the thermodynamics and statistics of the galaxies clustering affected by the dynamical dark energy. We consider two important dark energy models based on time dependent equation of state to evaluate the gravitational…

General Physics · Physics 2020-08-27 Behnam Pourhassan , Sudhaker Upadhyay

In this paper, we study interacting extended Chaplygin gas as dark matter and quintessence scalar field as dark energy with an effective $\Lambda$-term in Lyra manifold. As we know Chaplygin gas behaves as dark matter at the early universe…

General Relativity and Quantum Cosmology · Physics 2016-01-20 H. Saadat
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