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Related papers: Non-adiabatic dark fluid cosmology

200 papers

The present work aims to investigate an interacting Umami Chaplygin gas in the background dynamics of a spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) universe when adiabatic particle creation is allowed. Here, the universe is…

General Relativity and Quantum Cosmology · Physics 2024-12-30 Goutam Mandal , Sujay Kr. Biswas

We consider theories in which there exists a nontrivial coupling between the dark matter sector and the sector responsible for the acceleration of the universe. Such theories can possess an adiabatic regime in which the quintessence field…

Astrophysics · Physics 2008-11-26 Rachel Bean , Eanna E. Flanagan , Mark Trodden

This work explores the dynamical stability of cosmological models where dark matter and dark energy can non-minimally couple to spacetime (scalar) curvature. Two different scenarios are presented here. In the initial case, only dark matter…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Saddam Hussain , Anirban Chatterjee , Kaushik Bhattacharya

We present a discussion of the effects induced by bulk viscosity either on the very early Universe stability and on the dynamics associated to the extreme gravitational collapse of a gas cloud. In both cases the viscosity coefficient is…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Nakia Carlevaro , Giovanni Montani

In this work we present the cosmological dynamics of interacting dark energy models in the framework of particle creation mechanism. The particle creation mechanism presented here describes the true non equilibrium thermodynamics of the…

General Relativity and Quantum Cosmology · Physics 2017-06-07 Sujay Kr. Biswas , Wompherdeiki Khyllep , Jibitesh Dutta , Subenoy Chakraborty

In this paper we study a quintessence cosmological model in which the dark energy component is considered to be the Generalized Chaplygin Gas and the curvature of the three-geometry is taken into account. Two parameters characterize this…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Sergio del Campo , José Villanueva

We consider a Friedmann model of the universe with bulk viscous matter and radiation as the cosmic components. We study the asymptotic properties in the equivalent phase space by considering the three cases for the bulk viscous coefficient…

General Relativity and Quantum Cosmology · Physics 2019-05-13 Athira Sasidharan , Titus K Mathew

We analyze the effects induced by the bulk viscosity on the dynamics associated to the extreme gravitational collapse. Aim of the work is to investigate whether the presence of viscous corrections to the evolution of a collapsing gas cloud…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Nakia Carlevaro , Giovanni Montani

This paper is devoted to study the phase space analysis of isotropic and homogenous universe model by taking a noninteracting mixture of electromagnetic and viscous radiating fluids whose viscous pressure satisfies a nonlinear version of…

General Relativity and Quantum Cosmology · Physics 2017-03-08 M. Sharif , Saadia Mumtaz

In this work we study the evolution of a spatially flat Universe by considering a viscous dark matter and perfect fluids for dark energy and radiation, including an interaction term between dark matter and dark energy. In the first part, we…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 A. Hernández-Almada , Miguel A. García-Aspeitia , Juan Magaña , V. Motta

The truncated Israel-Stewart theory of irreversible thermodynamics is used to describe the bulk viscous pressure and the anisotropic stress in a class of spatially homogeneous viscous fluid cosmological models. The governing system of…

General Relativity and Quantum Cosmology · Physics 2010-04-06 R. J. van den Hoogen , A. A. Coley

We have studied bulk viscosity in the modified $f(Q, T)$ gravity theory formalism, where $Q$ represents the non-metricity and $T$ denotes the trace of energy-momentum tensor within a flat Friedmann-Lema\^{i}tre-Robertson-Walker metric…

General Relativity and Quantum Cosmology · Physics 2021-12-01 Simran Arora , S. K. J. Pacif , Abhishek Parida , P. K. Sahoo

The universe media is considered as a non-perfect fluid with bulk viscosity and described by a more general equation of state. We assume the bulk viscosity is a linear combination of the two terms: one is constant, and the other is…

Astrophysics · Physics 2009-03-19 Xin-He Meng , Jie Ren , Ming-Guang Hu

We study the evolution of a flat Friedmann-Robertson- Walker Universe, filled with a bulk viscous cosmological fluid, in the presence of variable gravitational and cosmological constants. The dimensional analysis of the model suggest a…

General Relativity and Quantum Cosmology · Physics 2009-09-25 J. A. Belinchon , T. Harko , M. K. Mak

This work presents a comprehensive investigation of a novel cosmological model that unifies the Modified Chaplygin Gas (MCG) equation of state with gravitationally induced matter creation and bulk viscous dissipation in a spatially flat…

General Relativity and Quantum Cosmology · Physics 2025-09-26 Yogesh Bhardwaj , C P Singh

We obtain the non-linear relation between cosmological density and velocity perturbations by examining their joint dynamics in a two dimensional density-velocity divergence phase space. We restrict to spatially flat cosmologies consisting…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-08 Sharvari Nadkarni-Ghosh

The article communicates an alternative route to suffice the late-time acceleration considering a bulk viscous fluid with viscosity coefficient $\zeta =\zeta _{0}+ \zeta _{1} H + \zeta _{2} H^{2}$, where $\zeta _{0}, \zeta _{1}, \zeta _{2}$…

General Relativity and Quantum Cosmology · Physics 2020-07-20 Simran Arora , Snehasish Bhattacharjee , P. K. Sahoo

Implementing the concept of Dark Fluid with a Chaplygin-like equation of state within General Relativity, we construct a new higher-dimensional, static, and spherically symmetric anti-de Sitter (AdS) black hole solution. Energy conditions…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Y. Sekhmani , G. G. Luciano , J. Rayimbaev , M. K. Jasim , A. Al-Badawi , S. K. Maurya

Some cosmological scenarios with bulk viscosity for the dark energy fluid are considered. Based on some considerations related to hydrodynamics, two different equations of state for dark energy are assumed, leading to power-law and…

General Relativity and Quantum Cosmology · Physics 2020-02-07 Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

Phantom dark energy is a proposal that explains the current observations that mildly favor the equation of state of dark energy $\omega^{de}$ crossing -1 at 68% confidence level. However, phantom fields are generally ruled out by…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-09 Hassan Amirhashchi