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Related papers: Bulk viscosity, interaction and the viability of p…

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Bulk viscosity, which characterizes the irreversible dissipative resistance of a fluid to volume changes, has been proposed as a potential mechanism for explaining both early- and late-time accelerated expansion of the Universe. In this…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-18 P. P. Avelino , A. R. Gomes , D. A. Tamayo

We explore the dynamical properties of a cosmological model that includes viscous effects in the dark matter sector of the fluid equations in a flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. The bulk viscous effects are…

General Relativity and Quantum Cosmology · Physics 2022-11-14 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

In this work we consider a recent proposal in which gravitational interactions are mediated via classical information and apply it to a relativistic context. We study a toy model of a quantized Friedman-Robertson-Walker (FRW) universe with…

General Relativity and Quantum Cosmology · Physics 2017-05-31 Natacha Altamirano , Paulina Corona-Ugalde , Kiran Khosla , Robert B. Mann , Gerard Milburn

In the present work, we study a cosmological model composed of a viscous dark matter interacting with decaying vacuum energy in a spatially flat Universe. In the first part, we find the analytical solution of different cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 Vinita Khatri , C. P. Singh , Milan Srivastava

In this study, we will look at an interacting dark energy model. In the framework of Friedmann-Robertson-Walker (FRW) space-time, we have made the hypothesis of an interacting scheme between two fields (dark matter (DM) and dark energy…

General Relativity and Quantum Cosmology · Physics 2023-11-27 J. K. Singh , Ritika Nagpal

The objective of the present work is to study a cosmological model for a spatially flat Universe whose constituents are a dark energy field and a matter field which includes baryons and dark matter. The constituents are supposed to be in…

General Relativity and Quantum Cosmology · Physics 2013-09-13 Gilberto M. Kremer , Octavio A. S. Sobreiro

We examine an interacting dark matter--variable vacuum energy model for a spatially flat Friedmann-Roberston-Walker spacetime, focusing on the appearance of cosmological singularities such as \emph{big rip, big brake, big freeze}, and…

General Relativity and Quantum Cosmology · Physics 2015-08-19 Luis P. Chimento , Martín G. Richarte

Bulk viscosity in cold dark matter is an appealing feature that introduces distinctive phenomenological effects in the cosmological setting as compared to the $\Lambda$CDM model. Under this view, we propose a general parametrization of the…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Gabriel Gómez , Guillermo Palma , Ángel Rincón , Norman Cruz , Esteban González

Non-gravitational interaction between two barotropic dark fluids, namely the pressureless dust and the dark energy in a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker model has been discussed. It is shown that for the interactions…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-30 Supriya Pan , Ankan Mukherjee , Narayan Banerjee

The present work is a second in the series of investigation of the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here, dark matter is chosen in the form of perfect fluid with…

General Physics · Physics 2019-06-21 Sujay Kr. Biswas , Subenoy Chakraborty

We examine the cosmological consequences of an alternative to the standard expression for bulk viscosity, one which was proposed to avoid the propagation of superluminal signals without the necessity of extending the space of variables of…

General Relativity and Quantum Cosmology · Physics 2016-04-08 Marcelo M. Disconzi , Thomas W. Kephart , Robert J. Scherrer

Recently, in [1] we developed a parametric reconstruction method to a homogeneous, isotropic and spatially flat Friedmann-Robertson-Walker (FRW) cosmological model filled of a fluid of dark energy (DE) with constant equation of state (EOS)…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-03 Freddy Cueva Solano , Ulises Nucamendi

We propose a bulk viscous unified dark matter scenario based on a nonlinear extension of the full causal Israel-Stewart theory. This framework allows the viscous fluid to remain far from equilibrium, an essential feature for a physically…

General Relativity and Quantum Cosmology · Physics 2025-12-16 Guillermo Palma , Gabriel Gomez

In this work we explore the thermodynamic aspects of dark energy for late future time universe in two different scenarios: as a perfect fluid with constant and variable equation of state parameter; and as dissipative fluid described by a…

General Relativity and Quantum Cosmology · Physics 2022-03-03 David Tamayo

In the context of a homogeneous and isotropic universe, we consider the degeneracy condition at the background level between two scenarios in which processes out of equilibrium are possible; this consideration allows us to deviate from the…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

We investigate interacting dark energy models in the framework of fractal cosmology. We discuss a fractal FRW universe filled with the dark energy and dark matter which interact with each other. We obtain the equation for the relative…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-29 O. A. Lemets , D. A. Yerokhin

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

Cosmological models where dark matter (DM) and dark energy (DE) interact with each other are the general scenarios in compared to the non-interacting models. The interaction is usually motivated from the phenomenological ground and thus…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Weiqiang Yang , Supriya Pan , Andronikos Paliathanasis

In this paper bulk viscosity is introduced to describe the effects of cosmic non-perfect fluid on the cosmos evolution and to build the unified dark energy (DE) with (dark) matter models. Also we derive a general relation between the bulk…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-14 X. H. Meng , X. Dou

In this work, we investigate the dynamics of bulk viscous models with decaying vacuum energy density (VED) in a spatially homogeneous and isotropic flat Friedmann-Lema\^{i}tre- Robertson-walker (FLRW) spacetime. We particularly are…

General Relativity and Quantum Cosmology · Physics 2024-01-10 C. P. Singh , Vinita Khatri