English
Related papers

Related papers: Simple Bianchi cosmologies with anisotropic Segre …

200 papers

The role of anisotropic components on the dark energy and the dynamics of the universe is investigated. An anisotropic dark energy fluid with different pressures along different spatial directions is assumed to incorporate the effect of…

General Physics · Physics 2018-04-16 B. Mishra , S. K. Tripathy , Pratik P Ray

We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy. The perfect fluid is taken to be the one obeying the usual equation of state, i.e., $p = \zeta \ve$, with…

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

A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

We study a dark energy model with non-zero anisotropic stress, either linked to the dark energy density or to the dark matter density. We compute approximate solutions that allow to characterise the behaviour of the dark energy model and to…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Wilmar Cardona , Lukas Hollenstein , Martin Kunz

We study the homogeneous and anisotropic evolution of Bianchi type-I spacetime driven by perfect fluid with shear viscosity. We obtain exact solutions by considering the simplest form of the equation of state wherein the pressure and the…

General Relativity and Quantum Cosmology · Physics 2024-07-22 Inyong Cho , Rajibul Shaikh

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

General Relativity and Quantum Cosmology · Physics 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin

We study the possible types of future singularities in the isotropic homogeneous cosmological models for the arbitrary equation of state of the contents of the Universe. We obtain all known types of these singularities as well as two new…

General Relativity and Quantum Cosmology · Physics 2016-09-27 S. L. Parnovsky

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

We study the isotropisation of the homogeneous but anisotropic Bianchi class A models in presence of a minimally coupled and massive scalar field with or without a perfect fluid. To this end, we use the Hamiltonian formalism of Arnowitt,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stephane Fay

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

General Relativity and Quantum Cosmology · Physics 2012-06-18 Suresh Kumar , Ozgur Akarsu

The properties of a spherically symmetric static space-time permeated of dark energy are worked out. Dark energy is viewed as the strain energy of an elastically deformable four dimensional manifold. The metric is worked out in the vacuum…

General Relativity and Quantum Cosmology · Physics 2015-06-04 N. Radicella , M. Sereno , A. Tartaglia

The paper deals with a spatially homogeneous and anisotropic universe filled with perfect fluid and dark energy components. The two sources are assumed to interact minimally together with a special law of variation for the average Hubble's…

General Physics · Physics 2014-08-27 Suresh Kumar , Anil Kumar Yadav

We study Bianchi type $I$ cosmological model in the presence of magnetized anisotropic dark energy. The energy-momentum tensor consists of anisotropic fluid with anisotropic EoS $p=\omega{\rho}$ and a uniform magnetic field of energy…

General Relativity and Quantum Cosmology · Physics 2010-11-03 M. Sharif , M. Zubair

Given that the dark matter and dark energy in the universe affect cosmological observables only gravitationally, their phenomenology may be described by a single stress energy tensor. True unification however requires a theory that…

Astrophysics · Physics 2008-11-26 Dimitrios Giannakis , Wayne Hu

Classifying the zero-temperature ground states of quantum field theories with finite charge density is a very interesting problem. Via holography, this problem is mapped to the classification of extremal charged black brane geometries with…

High Energy Physics - Theory · Physics 2015-06-12 Norihiro Iizuka , Shamit Kachru , Nilay Kundu , Prithvi Narayan , Nilanjan Sircar , Sandip P. Trivedi , Huajia Wang

In this study, we have explored a scalar field cosmological model in the axially symmetric Bianchi type-I universe. In this study, our aim is to constrain the scalar field dark energy model in an anisotropic background. For this purpose,…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav

The Bianchi type III dark energy models with constant deceleration parameter are investigated. The equation of state parameter $\omega$ is found to be time dependent and its existing range for this model is consistent with the recent…

General Relativity and Quantum Cosmology · Physics 2011-01-05 Anil Kumar Yadav , Lallan Yadav

Wide area cosmological surveys enable investigation of whether dark energy properties are the same in different directions on the sky. Cosmic microwave background observations strongly restrict any dynamical effects from anisotropy, in an…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-05 Stephen A. Appleby , Eric V. Linder

In this article, we investigated a Locally Rotationally Symmetric (LRS) Bianchi-II cosmological model with matter and Holographic Dark Energy (HDE) in the context of $f(R)$ theory of gravity. In order to find exact solutions to the field…

General Relativity and Quantum Cosmology · Physics 2023-07-03 A. Y. Shaikh , D. P. Tadas , S. D. Katore

We investigate the observational effects of a quintessence model in an anisotropic spacetime. The anisotropic metric is a non-rotating particular case of a generalized Godel's metric and is classified as Bianchi III. This metric is an exact…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-23 W. Miranda , S. Carneiro , C. Pigozzo