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Related papers: The Umami Chaplygin Model

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The standard model of cosmology considers the existence of two components of unknown nature, ``dark matter'' and ``dark energy'', which determine the cosmological evolution. Their nature remains unknown, and other models can also be…

Astrophysics · Physics 2007-05-23 A. Arbey

In the framework of spatially averaged inhomogeneous cosmologies in classical general relativity, effective Einstein equations govern the dynamics of averaged scalar variables in a scale--dependent way. A particular cosmology may be…

General Relativity and Quantum Cosmology · Physics 2010-08-23 Xavier Roy , Thomas Buchert

In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by Loop quantum cosmology. Dark energy in the form of Generalised Cosmic Chaplygin gas is…

General Physics · Physics 2015-06-04 Ratul Chowdhury , Prabir Rudra

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

We explore a generalised unified dark energy model that incorporates a non-minimal interaction between a tachyonic fluid and an additional scalar field. Specifically, we require that the second field possesses a vacuum energy, introducing…

General Relativity and Quantum Cosmology · Physics 2023-08-31 Peter K. S. Dunsby , Orlando Luongo , Marco Muccino

The hypothesis that dark matter and dark energy are unified through the Chaplygin gas is reexamined. Using generalizations of the spherical model which incorporate effects of the acoustic horizon we show that an initially perturbative…

Astrophysics · Physics 2008-11-26 Neven Bilic , Robert J. Lindebaum , Gary B. Tupper , Raoul D. Viollier

Unified dark matter cosmologies economically combine missing matter and energy in a single fluid. Of these models, the standard Chaplygin gas is theoretically motivated, but faces problems in explaining large scale structure if linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Abdelrahman Abdullah , Amr El-Zant , Ali Ellithi

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

In this paper we show that a \emph{one-to-one} correspondence exists between any dark energy model and an equivalent (from a cosmological point of view, in the absence of perturbations) quartessence model in which dark matter and dark…

Astrophysics · Physics 2009-11-11 L. M. G. Beca , P. P. Avelino

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

In the very last years, cosmological models where the properties of the dark components of the Universe - dark matter and dark energy - are accounted for by a single "dark fluid" have drawn increasing attention and interest. Amongst many…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-02 Stefano Camera , Carmelita Carbone , Lauro Moscardini

In this work we explore an alternative phenomenological model to Chaplygin gas proposed by H. Hova et. al., consisting on a modification of a perfect fluid, to explain the dynamics of dark matter and dark energy at cosmological scales…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-30 A. Hernandez-Almada , Juan Magana , Miguel A. Garcia-Aspeitia , V. Motta

In this paper we study the perturbations of a cosmic multi-fluid medium consisting of radiation, dust and a Chaplygin gas. To do so, we follow the 1 + 3 covariant formalism and derive the evolution equations of the fluctuations in the…

General Relativity and Quantum Cosmology · Physics 2020-10-27 Shambel Sahlu , Heba Sami , Anna-Mia Swart , Thato Tsabone , Maye Elmardi , Amare Abebe

Any unified dark matter cosmology can be decomposed into dark matter interacting with vacuum energy, without introducing any additional degrees of freedom. We present observational constraints on an interacting vacuum plus dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-16 Yuting Wang , David Wands , Lixin Xu , Josue De-Santiago , Alireza Hojjati

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

In this paper, we present a unified scheme based on the fluid description of the dark sector of the universe. The scheme captures models with interaction between dark energy and dark matter, being the core of generalization the time-varying…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-20 W. J. C. da Silva , J. E. Gonzalez , R. Silva , J. S. Alcaniz

The standard model of cosmology suggests the existence of two components, "dark matter" and "dark energy", which determine the fate of the Universe. Their nature is still under investigation, and no direct proof of their existences has…

Astrophysics · Physics 2009-07-09 A. Arbey

The universe content is considered as a non-perfect fluid with bulk viscosity and can be described by a general equation of state (endowed some deviation from the conventionally assumed cosmic perfect fluid model). An explicitly bulk…

Astrophysics · Physics 2009-10-16 X H Meng , X Dou

We investigate the unification scenario provided by the generalised Chaplygin gas model (a perfect fluid characterized by an equation of state p = -A/\rho^{\alpha}). Our concerns lie with a possible tension existing between background…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Juliano Pereira Campos , Júlio César Fabris , Rafael Perez , Oliver F. Piattella , Hermano Velten

We investigate models of interacting dark matter and dark energy for the universe in a spatially flat Friedmann-Robertson-Walker (FRW) space-time. We find the "source equation" for the total energy density and determine the energy density…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Luis P. Chimento