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In this work interacting Umami Chaplygin gas has been studied in flat FRW model of universe in context of it's thermodynamic and dynamical behaviour. In particular, considering Umami fluid as dark energy interacting with dark matter,…

General Physics · Physics 2021-05-12 Sujay Kr. Biswas , Atreyee Biswas

A gauge-invariant, linear cosmological perturbation theory of an almost homogeneous and isotropic universe with dynamically evolving Newton constant G and cosmological constant $\Lambda$ is presented. The equations governing the evolution…

General Relativity and Quantum Cosmology · Physics 2011-04-22 Adriano Contillo

The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-13 Shulei Cao

For general number of spatial dimensions we investigate the cosmological dynamics driven by a cosmological constant and by a source with barotropic equation of state. It is assumed that for both those sources the energy density can be…

General Relativity and Quantum Cosmology · Physics 2022-11-09 A. A. Saharian , R. M. Avagyan , E. R. Bezerra de Mello , V. Kh. Kotanjyan , T. A. Petrosyan , H. G. Babujyan

In this paper, we undertake a unified study of background dynamics and cosmological perturbations in the presence of the Chaplygin gas. This is done by first constraining the background cosmological parameters of different Chaplygin gas…

General Relativity and Quantum Cosmology · Physics 2023-10-12 Shambel Sahlu , Heba Sami , Renier Hough , Maye Elmardi , Anna-Mia Swart , Amare Abebe

The Universe is modeled as a binary mixture whose constituents are described by a van der Waals fluid and by a dark energy density. The dark energy density is considered either as the quintessence or as the Chaplygin gas. The irreversible…

General Relativity and Quantum Cosmology · Physics 2009-11-10 G. M. Kremer

We study the consequences of a homogeneous dark energy fluid having a non-vanishing velocity with respect to the matter and radiation large-scale rest frames. We consider homogeneous anisotropic cosmological models with four fluids…

Astrophysics · Physics 2008-11-26 Jose Beltran Jimenez , Antonio L. Maroto

We introduce a cosmological model in the framework of Generalised Massive Gravity. This theory is an extension of non-linear massive gravity with a broken translation symmetry in the St\"uckelberg space. In a recent work, we showed the…

General Relativity and Quantum Cosmology · Physics 2020-11-25 Michael Kenna-Allison , A. Emir Gumrukcuoglu , Kazuya Koyama

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

We present a Friedmann-Robertson-Walker quantum cosmological model in the presence of Chaplygin gas and perfect fluid for early and late time epoches. In this work, we consider perfect fluid as an effective potential and apply Schutz's…

General Relativity and Quantum Cosmology · Physics 2008-11-26 P. Pedram , S. Jalalzadeh

A spatially flat Friedmann-Robertson-Walker(FRW) cosmological model with generalized Chaplygin gas is studied in the context of scalar-metric formulation of cosmology. Schutz's mechanism for the perfect fluid is applied with generalized…

General Relativity and Quantum Cosmology · Physics 2011-06-24 Barun Majumder

Some cosmological models based on the gravitational theory $f(R) = R+\zeta R^2$, and on fluids obeying to the equations of state of Redlich-Kwong, Berthelot, and Dieterici are proposed for describing smooth transitions between different…

General Relativity and Quantum Cosmology · Physics 2021-10-27 Saikat Chakraborty , Daniele Gregoris

The cosmological application of a dark viscous fluid in a spatially flat Friedmann-Robertson-Walker (FRW) universe with a modified logarithmic equation of state (EoS), being an analogue of the equation associated with the isotropic…

General Relativity and Quantum Cosmology · Physics 2026-04-02 I. Brevik , A. V. Timoshkin

Fluid cosmologies are consistent with the generally accepted observational evidence during intermediate and late times, and they need not have singular behavior in primordial times. A general form for fluid cosmology consistent with…

General Relativity and Quantum Cosmology · Physics 2009-01-20 James Lindesay

Currently, a large amount of data implies that the matter constituents of the cosmological dark sector might be collisional. An attractive feature of such a possibility is that, it can reconcile dark matter (DM) and dark energy (DE) in…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-25 K. Kleidis , N. K. Spyrou

In this paper a possibility of the accelerated expansion of the large scale universe with a varying polytropic fluid of a certain type is presented. About a special role of non-gravitational interactions between dark energy and dark matter,…

General Relativity and Quantum Cosmology · Physics 2017-07-14 Martiros Khurshudyan , Asatur Khurshudyan

The Chaplygin gas has been proposed as a possible dark energy, dark matter candidate. As a working fluid in a Friedmann-Robertson-Walker universe, it exhibits early behavior reminiscent of dark matter, but at later times is more akin to a…

General Relativity and Quantum Cosmology · Physics 2011-03-07 T. C. Lipscombe

In this paper, we have considered a model of modified Chaplygin gas in VSL theory with variable gravitational constant $G$. We have shown that the evolution of the universe starts from radiation era to phantom model. The whole evolution of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anup Kumar Singha , Ujjal Debnath

We use the formalism of geometrothermodynamics (GTD) to derive fundamental thermodynamic equations that are used to construct general relativistic cosmological models. In particular, we show that the simplest possible fundamental equation,…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Alejandro Aviles , Aztlán Bastarrachea-Almodovar , Lorena Campuzano , Hernando Quevedo

In the present work, we have made an attempt to investigate the dark energy possibility from the thermodynamical point of view. For this purpose, we have studied thermodynamic stability of three popular dark energy models in the framework…

General Relativity and Quantum Cosmology · Physics 2021-01-18 Abdulla Al Mamon , Pritikana Bhandari , Subenoy Chakraborty
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