English
Related papers

Related papers: Phase Space Analysis for Anisotropic Universe with…

200 papers

An asymptotic stability analysis of spatially homogeneous models of Bianchi type containing tilted perfect fluids is performed. Using the known attractors for the non-tilted Bianchi type universes, we check whether they are stable against…

General Relativity and Quantum Cosmology · Physics 2009-11-10 John D. Barrow , Sigbjorn Hervik

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

Bianchi I cosmological models consisting of a fluid with both bulk and shear viscosity are studied. It is shown how the dynamical importance of the shear and the fluid density change in the course of evolution. Exact solutions with an…

General Relativity and Quantum Cosmology · Physics 2021-03-15 A. Banerjee , S. B. Duttachoudhury , Abhik Kumar Sanyal

Multidimensional cosmological model describing the evolution of a fluid with shear and bulk viscosity in $n$ Ricci-flat spaces is investigated. The barotropic equation of state for the density and the pressure in each space is assumed. The…

General Relativity and Quantum Cosmology · Physics 2010-04-30 V. R. Gavrilov , V. N. Melnikov , Roland Triay

We have investigated an LRS Bianchi Type I models with bulk viscosity in the cosmological theory based on Lyra's geometry. A new class of exact solutions have been obtained by considering a time-dependent displacement field for a constant…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Anirudh Pradhan , Hare Ram Pandey

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

We present a new framework for testing the isotropy of the Universe using cosmic microwave background data, building on the nested-sampling ANICOSMO code. Uniquely, we are able to constrain the scalar, vector and tensor degrees of freedom…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-08 Daniela Saadeh , Stephen M. Feeney , Andrew Pontzen , Hiranya V. Peiris , Jason D. McEwen

Despite having a reasonably successful account of accelerated cosmology, understanding the early evolution of Universe has always been difficult for mankind. Our promising strategy is based on a novel class of symmetric teleparallel…

General Relativity and Quantum Cosmology · Physics 2022-09-12 L. Anjana Devi , S. Surendra Singh , Leishingam Kumrah , Md Khurshid Alam

The study of a self-consistent system of nonlinear spinor and Bianchi type I gravitational fields in presence of a viscous fluid and $\Lambda$ term with the spinor field nonlinearity being some arbitrary functions of the invariants $I$ an…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , Victor Rikhvitsky

In this paper, aniostropic dark energy cosmological models have been constructed in a Bianchi-V space-time with the energy momentum tensor consisting of two non-interacting fluids namely bulk viscous fluid and dark energy fluid. Two…

General Relativity and Quantum Cosmology · Physics 2018-02-01 B. Mishra , Pratik P. Ray , S. K. J. Pacif

The dynamics of cosmological anisotropies is investigated for Bianchi type I universe filled by a relativistic matter represented by the reduced relativistic gas model (RRG), with equation of state interpolating between radiation and…

General Relativity and Quantum Cosmology · Physics 2019-08-20 Simpliciano Castardelli dos Reis , Ilya L. Shapiro

Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Paulo Aguiar , Paulo Crawford

We study the dynamical evolution of an $f(R)$ model of gravity in a viscous and anisotropic background which is given by a Bianchi type-I model of the Universe. We find viable forms of $f(R)$ gravity in which one is exactly the Einsteinian…

General Physics · Physics 2014-01-20 Kh. Saaidi , A. Aghamohammadi , H. Hossienkhani

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

In this paper we have investigated the general form of viscous and non-viscous dark energy equation of state (EoS) parameter in the scope of anisotropic Bianchi type I space-time. We show that the presence of bulk viscosity causes…

General Relativity and Quantum Cosmology · Physics 2014-03-20 Hassan Amirhashchi , Anirudh Pradhan

We discuss the problem of the stability of the isotropy of the universe in the space of ever-expanding spatially homogeneous universes with a compact spatial topology. The anisotropic modes which prevent isotropy being asymptotically stable…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John D. Barrow , Hideo Kodama

The paper deals with Bianchi type V Universe, which has dynamical energy density. We consider Bianchi type V space-time, introducing three different skewness parameters along spatial directions to quantify the deviation of pressure from…

General Physics · Physics 2015-03-17 Anil Kumar Yadav

We propose a scenario in which the dark components of the Universe are manifestations of a single bulk viscous fluid. Using dynamical system methods, a qualitative study of the homogeneous, isotropic background scenario is performed in…

Astrophysics · Physics 2008-12-18 R. Colistete , J. C. Fabris , J. Tossa , W. Zimdahl

A fundamental assumption in the standard model of cosmology is that the Universe is isotropic on large scales. Breaking this assumption leads to a set of solutions to Einstein's field equations, known as Bianchi cosmologies, only a subset…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-23 Daniela Saadeh , Stephen M. Feeney , Andrew Pontzen , Hiranya V. Peiris , Jason D. McEwen

A plane-symmetric non-static cosmological model representing a bulk viscous fluid distribution has been obtained which is inhomogeneous and anisotropic and a particular case of which is gravitationally radiative. Without assuming any {\it…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Anirudh Pradhan , Hare Ram Pandey
‹ Prev 1 3 4 5 6 7 10 Next ›