English
Related papers

Related papers: Bulk Viscous cosmological models in Lyra geometry

200 papers

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 manuscript is devoted to investigate Bianchi Type $I$ universe in the context of $f(R,T)$ gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type $I$ spacetime. The modified field…

General Physics · Physics 2015-08-07 M. Farasat Shamir

In this paper, we explore an axially symmetric Bianchi type-I model of the universe with bulk viscous fluid as a source of gravitational field under the framework of Einstein's field equations by assuming barotropic bulk viscous pressure as…

General Relativity and Quantum Cosmology · Physics 2025-04-29 G. K. Goswami , Anirudh Pradhan , Vipin Chandra Dubey

The research on relativistic universe models with viscous fluids is reviewed. Viscosity may have been of significance during the early inflationary era, and may also be of importance for the late time evolution of the Universe. Bulk…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Iver Brevik , Øyvind Grøn

The present study deals with locally rotationally symmetric (LRS) Bianchi type II cosmological models representing massive string. The energy-momentum tensor for such string as formulated by Letelier (1983) is used to construct massive…

General Physics · Physics 2015-03-18 Anil Kumar Yadav , Anirudh Pradhan , Archana Singh

The dynamics of a class of cosmological models with collisionless matter and four Killing vectors is studied in detail and compared with that of corresponding perfect fluid models. In many cases it is possible to identify asymptotic states…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. D. Rendall , K. P. Tod

We consider the dynamics of a barotropic cosmological fluid in an anisotropic, Bianchi type I space-time in Eddington-inspired Born-Infeld (EiBI) gravity. By assuming an isotropic pressure distribution, we obtain the general solution of the…

General Relativity and Quantum Cosmology · Physics 2014-10-30 Tiberiu Harko , Francisco S. N. Lobo , M. K. Mak

The standard formulation of General Relativity Theory, in the absence of a cosmological constant, is unable to explain the responsible mechanism for the observed late-time cosmic acceleration. On the other hand, by inserting the…

General Relativity and Quantum Cosmology · Physics 2022-12-26 Raja Solanki , Simran Arora , P. K. Sahoo , P. H. R. S. Moraes

The general solution of the gravitational field equations for a full causal bulk viscous stiff cosmological fluid, with bulk viscosity coefficient proportional to the energy density to the power 1/4, is obtained in the flat…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , T. Harko

Bianchi type V matter filled universe with varying lambda in general relativity are investigated by using the law of variation for the generalized mean Hubble parameter. This yields the constant value of deceleration parameter and generates…

General Relativity and Quantum Cosmology · Physics 2013-01-15 Anil Kumar Yadav

Conformally flat spherically symmetric cosmological models representing a charged perfect fluid as well as a bulk viscous fluid distribution have been obtained. The cosmological constant \Lambda is found positive and is a decreasing…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Anirudh Pradhan , Om Prakash Pandey

We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VI$_{-1/9}$ using dynamical systems methods and numerical simulations. We study models with and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S Hervik , R J van den Hoogen , W C Lim , A A Coley

A recently proposed nonlinear transport equation is used to model bulk viscous cosmologies that may be far from equilibrium, as happens during viscous fluid inflation or during reheating. The asymptotic stability of the de Sitter and…

General Relativity and Quantum Cosmology · Physics 2009-10-30 L Chimento , A Jakubi , V Mendez , R Maartens

In this paper, we investigate a scalar field Brans-Dicke cosmological model in Lyra's geometry which is based on the modifications in geometrical term as well as energy term of Einstein's field equations. We have examined the validity of…

General Relativity and Quantum Cosmology · Physics 2023-11-15 Rajendra Prasad , Lalit Kumar Gupta , Anil Kumar Yadav

Bulk viscosity is the only viscous influence that can change the background dynamics in a homogeneous and isotropic universe. In the present work, we analyze the bulk viscous cosmological model with the bulk viscosity coefficient of the…

General Relativity and Quantum Cosmology · Physics 2021-12-13 Gaurav Gadbail , Simran Arora , P. K. Sahoo

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

The objective of this work enclosed with the study of spatially homogeneous anisotropic Bianchi type-I universe in $f(R,T)$ gravity (where $R$ is the Ricci scalar and $T$ is the trace of stress energy momentum tensor) in two different cases…

General Relativity and Quantum Cosmology · Physics 2017-03-20 P. K. Sahoo , Parbati Sahoo , Binaya K. Bishi

The behaviour of solutions to the Einstein equations with a causal viscous fluid source is investigated. In this model we consider a spatially flat Robertson-Walker metric, the bulk viscosity coefficient is related to the energy density as…

General Relativity and Quantum Cosmology · Physics 2012-08-09 Luis P. Chimento , Alejandro S. Jakubi

In this paper, we study the viscous fluid cosmological model that when certain conditions are invoked mimics the $\Lambda$CDM model. The background equations governing the evolution of viscous interacting fluids in a multifluid system are…

General Relativity and Quantum Cosmology · Physics 2024-12-09 BG Mbewe , RR Mekuria , S Sahlu , A Abebe

The standard formulation of general relativity fails to describe some recent interests in the universe. It impels us to go beyond the standard formulation of gravity. The $f(Q)$ gravity theory is an interesting modified theory of gravity,…

General Relativity and Quantum Cosmology · Physics 2022-04-14 Sanjay Mandal , Abhishek Parida , P. K. Sahoo