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A model for a flat homogeneous and isotropic Universe composed of dark energy, dark matter, neutrinos, radiation and baryons is analyzed. The fields of dark matter and neutrinos are supposed to interact with the dark energy. The dark energy…

General Relativity and Quantum Cosmology · Physics 2008-11-26 G. M. Kremer

We reconsider the dynamics of the Universe in the presence of interactions in the cosmological dark sector. A class of interacting models is introduced via a real function $f\left(r\right)$ of the ratio $r$ between the energy densities of…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-09 R. von Marttens , L. Casarini , D. F. Mota , W. Zimdahl

We study CMB constraints on a model with a cosmological constant and a fraction of dark matter non-minimally coupled to a massless scalar field. In this scenario, there is an extra gravity-like fifth force which can affect the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-09 Sophie C. F. Morris , Anne M. Green

Cosmic Microwave Background satellite missions as the on-going Planck experiment are expected to provide the strongest constraints on a wide set of cosmological parameters. Those constraints, however, could be weakened when the assumption…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-28 Matteo Martinelli , Laura Lopez Honorez , Alessandro Melchiorri , Olga Mena

The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-18 Weiqiang Yang , Lixin Xu

In this work, we have considered interacting dynamical model taking variable modified Chaplygin gas which plays as dark energy coupled to cold dark matter in the flat FRW universe. Since the nature of dark energy and dark matter is still…

General Physics · Physics 2015-03-19 Jhumpa Bhadra , Ujjal Debnath

We combine recent measurements of Cosmic Microwave Background Anisotropies, Supernovae luminosity distances and Baryonic Acoustic Oscillations to derive constraints on the dark energy equation of state w in the redshift range 0<z<2, using a…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-28 Najla Said , Carlo Baccigalupi , Matteo Martinelli , Alessandro Melchiorri , Alessandra Silvestri

In this work we investigate the interaction between dark matter and dark energy for a coupling that obeys the Wang-Meng decaying law, $\rho_{{\rm DM}}\propto (1+z)^{3-\epsilon}$, and the Barboza-Alcaniz dark energy parametric model,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Rafael C. Nunes , Edésio M. Barboza

We examine how the properties of dark matter, parameterised by an equation of state parameter $w$ and two perturbative Generalised Dark Matter (GDM) parameters $c^2_s$ (the sound speed) and $c^2_\text{vis}$ (the viscosity), are constrained…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-04 Daniel B. Thomas , Michael Kopp , Constantinos Skordis

This paper is devoted to the investigation of modified Chaplygin gas model in the context of solvable k-essence cosmologies. For this purpose, we construct equations of state parameter of this model for some particular values of the…

General Physics · Physics 2012-07-31 M. Sharif , K. R. Yesmakhanova , S. Rani , R. Myrzakulov

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

We consider unified dark sector models in which the fluid can collapse and cluster into halos, allowing for hierarchical structure formation to proceed as in standard cosmology. We show that both background evolution and linear…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-05 Mahmoud Hashim , Amr El-Zant

The growth of large scale structure is studied in a universe containing both cold dark matter (CDM) and generalized Chaplygin gas (GCg). GCg is assumed to contribute only to the background evolution of the universe while the CDM component…

Astrophysics · Physics 2009-11-10 T. Multamaki , M. Manera , E. Gaztanaga

In this paper, we propose a new unified dark fluid (UDF) model with equation of state (EoS) $w(a)=-\alpha/(\beta a^{-n}+1)$, which includes the generalized Chaplygin gas model (gGg) as its special case, where $\alpha$, $\beta$ and $n$ are…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-22 Lixin Xu

Motivated by the cosmological constant and the coincidence problems, we consider a cosmological model where the cosmological constant $\Lambda_0$ is replaced by a cosmological term $\Lambda(t)$ which is allowed to vary in time. More…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-24 Vincent Poitras

A decomposed generalised Chaplygin gas (gCg) with energy flux from dark energy to dark matter, represented by a negative value for the gas parameter $\alpha$, is shown to alleviate the tension between EDGES data and the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-10 C. Pigozzo , S. Carneiro , J. C. Fabris

The interacting dark energy model could propose a effective way to avoid the coincidence problem. In this paper, dark energy is taken as a fluid with a constant equation of state parameter $w_x$. In a general gauge, we could obtain two sets…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-10 Weiqiang Yang , Lixin Xu

We constrain the parameters of dynamical dark energy in the form of a classical or tachyonic scalar field with barotropic equation of state jointly with other cosmological ones using the combined datasets which include the CMB power spectra…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Olga Sergijenko , Ruth Durrer , Bohdan Novosyadlyj

We study the holographic and agegraphic dark energy models without interaction using the latest observational Hubble parameter data (OHD), the Union2.1 compilation of type Ia supernovae (SNIa), and the energy conditions. Scenarios of dark…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 Ming-Jian Zhang , Cong Ma , Zhi-Song Zhang , Zhong-Xu Zhai , Tong-Jie Zhang

We perform a detailed comparison between the Logotropic model [P.H. Chavanis, Eur. Phys. J. Plus 130 (2015) 130] and the $\Lambda$CDM model. These two models behave similarly at large (cosmological) scales up to the present. Differences…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Pierre-Henri Chavanis , Suresh Kumar
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