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Related papers: Some Homogeneous Bianchi Type IX Viscous Fluid Cos…

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We consider a unified dissipative dark fluid model. Our fluid contains an adiabatic part plus a bulk viscous one. The adiabatic part has the ability to asymptote between two power laws and so can interpolate between the dust and dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-16 Esraa Elkhateeb

In this paper, we study anisotropic Bianchi-V universe with magnetic field and bulk viscous fluid in string cosmology. Exact solutions of the field equations are obtained by using the equation of state for a cloud of strings, and a…

General Relativity and Quantum Cosmology · Physics 2012-11-28 C. P. Singh , Vijay Singh

In this paper, we investigate a cosmological model based on viscous $f(R,T)$ gravity as a potential alternative to dark energy. This model incorporates bulk viscosity and is analyzed using an effective equation of state. We consider the…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-26 M. Koussour , A. Altaibayeva , S. Bekov , O. Donmez , S. Muminov , J. Rayimbaev

We investigate a biaxial Bianchi IX model with positive cosmological constant, which is sometimes called the Lambda-Taub-NUT spacetime, whose exact solution is well known. The minisuperspace of biaxial Bianchi IX models admits two…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Kento Osuga , Don N. Page

Within the framework of the minimum quadratic Poincare gauge theory of gravity in the Riemann-Cartan spacetime the dynamics of homogeneous anisotropic Bianchi types I-IX spinning-fluid cosmological models is investigated. A basic equation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nguyen Hong Chuong , Nguyen Van Hoang

Some anisotropic Bianchi V dark energy models are investigated in a scale invariant theory of gravity. We consider two non interacting fluids such as dark energy and a bulk viscous fluid. Dark energy pressure is considered to be anisotropic…

General Relativity and Quantum Cosmology · Physics 2017-10-25 S. K. Tripathy , B. Mishra , P. K. Sahoo

This paper is devoted to study the Bianchi type III model in the presence of anisotropic fluid in f(R) gravity. Exponential and power-law volumetric expansions are used to obtain exact solutions of the field equations. We discuss the…

General Relativity and Quantum Cosmology · Physics 2011-02-16 M. Sharif , H. Rizwana Kausar

In this paper, we have investigated Bianchi type VIh, II and III cosmological model with wet dark fluid in scale invariant theory of gravity, where the matter field is in the form of perfect fluid and with a time dependent gauge function…

General Relativity and Quantum Cosmology · Physics 2017-02-01 B. Mishra , P. K. Sahoo

In this study, we have demonstrated the expansion history of an axially symmetric Bianchi type-I model of the universe. Our model as of now presents an accelerating universe, which had been in the decelerating phase in the past. Roles of…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Vinod Kumar Bhardwaj , Archana Dixit , Rita Rani , G. K. Goswami , Anirudh Pradhan

We study the dynamics of the vacuum Bianchi IX model with timelike singularity and compare it with the dynamics of the Bianchi IX model with cosmological singularity. We show that differences in the signs of some terms in the set of…

General Relativity and Quantum Cosmology · Physics 2017-06-27 S. L. Parnovsky , W. Piechocki

A model of a cloud formed by massive strings is used as a source of LRS Bianchi type II with time decaying vacuum energy density $\Lambda$. To construct string cosmological models we have used the energy-momentum tensor for such string as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-29 Hassan Amirhashchi

We study the evolution of a flat Friedmann-Robertson-Walker Universe, filled with a bulk viscous cosmological fluid, in the presence of time varying ``constants''. The dimensional analysis of the model suggests a proportionality between the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 José Antonio Belinchón , Indrajit Chakrabarty

We use a dynamical systems approach based on the method of orthonormal frames to study the dynamics of a two-fluid, non-tilted Bianchi Type I cosmological model. In our model, one of the fluids is a fluid with bulk viscosity, while the…

General Relativity and Quantum Cosmology · Physics 2015-10-22 Ikjyot Singh Kohli , Michael C. Haslam

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 investigate in detail the qualitative behaviour of the class of Bianchi type B spatially homogeneous cosmological models in which the matter content is composed of two non-interacting components; the first component is described by a…

General Relativity and Quantum Cosmology · Physics 2014-11-17 A. P. Billyard , A. A. Coley , R. J. van den Hoogen , J. Ibanez , I. Olasagasti

In a recent paper \cite{1}, we have studied the vacuum solutions of Bianchi types I and V spacetimes in the framework of metric f(R) gravity. Here we extend this work to perfect fluid solutions. For this purpose, we take stiff matter to…

General Relativity and Quantum Cosmology · Physics 2010-10-28 M. Sharif , M. Farasat Shamir

We consider the Bianchi I geometry coupled to several species of comoving barotropic perfect fluids with a linear equation of state in the context of general relativity. The solution of the dynamics can be reduced to a quadrature, which can…

General Relativity and Quantum Cosmology · Physics 2024-10-29 David Brizuela , Sara F. Uria

The general form of the anisotropy parameter of the expansion for Bianchi type-III metric is obtained in the presence of a single diagonal imperfect fluid with a dynamically anisotropic equation of state parameter and a dynamical energy…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Ozgur Akarsu , Can B. Kilinc

The present study deals with Lyra's geometry in plane symmetric metric discussed in the presence of bulk viscous fluid and one dimensional strings are assumed to be loaded with particles and the particle energy density. The variation of…

General Relativity and Quantum Cosmology · Physics 2023-06-21 M Krishna , SobhanBabu Kappala , R Santhikumar

The viscous Cardassian cosmology is discussed, assuming that there is a bulk viscosity in the cosmic fluid. The dynamical analysis indicates that there exists a singular curve in the phase diagram of viscous Cardassian model. In the viscous…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Chang-Bo Sun , Jia-Ling Wang , Xin-Zhou Li