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Related papers: Bianchi type-II cosmological model: some remarks

200 papers

We consider the problem of late-time isotropization in spatially homogeneous but anisotropic cosmological models when the source of the gravitational field consists of two non-interacting perfect fluids -- one tilted and one non-tilted. In…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Martin Goliath , Ulf S. Nilsson

We numerically investigate the solutions to the effective equations of the Bianchi II model within the "improved" Loop Quantum Cosmology (LQC) dynamics. The matter source is a massless scalar field. We perform a systematic study of the…

General Relativity and Quantum Cosmology · Physics 2012-10-08 Alejandro Corichi , Edison Montoya

Within the scope of Bianchi type-III spacetime we study the role of spinor field on the evolution of the Universe as well as the influence of gravity on the spinor field. In doing so we have considered a polynomial type of nonlinearity. In…

General Relativity and Quantum Cosmology · Physics 2016-03-16 Bijan Saha

In this manuscript, we investigate the oscillatory behaviour of the anisotropy in the diagonal Bianchi-I spacetimes. Our starting point is a simplification of Einstein's equations using only observable or physical variables. As a…

General Relativity and Quantum Cosmology · Physics 2021-04-02 Leandro G Gomes , Bruno B. Bizarria , Gabriel A. de Souza Silva , William O. Clavijo

The present study deals with spatially homogeneous and totally anisotropic locally rotationally symmetric (LRS) Bianchi type I cosmological model with variable $G$ and $\Lambda$ in presence of imperfect fluid. To get the deterministic model…

General Physics · Physics 2012-01-17 Anil Kumar Yadav , Anirudh Pradhan , Ajay Kumar Singh

The present study deals with spatially homogeneous and anisotropic Bianchi-I cosmological model representing massive strings. The energy-momentum tensor, as formulated by Letelier (Phys. Rev. D 28: 2414, 1983) has been used to construct…

General Physics · Physics 2014-03-11 Chanchal Chawla , R. K. Mishra , Anirudh Pradhan

Anisotropic cloud string cosmological model with Bianchi type I space time is investigated in the context of general relativity. The exact solutions of Einstein field equations are obtained with when the source for energy momentum tensor is…

General Physics · Physics 2019-09-26 Kangujam Priyokumar Singh , Meher Daimary

We study Dirac spinors in Bianchi type-I cosmological models, within the framework of torsional $f(R)$-gravity. We find four types of results: the resulting dynamic behavior of the universe depends on the particular choice of function…

General Relativity and Quantum Cosmology · Physics 2011-11-14 Stefano Vignolo , Luca Fabbri , Roberto Cianci

The (twice-contracted) second Bianchi identity is a differential curvature identity that holds on any smooth manifold with a metric. In the case when such a metric is Lorentzian and solves Einstein's equations with an (in this case…

General Relativity and Quantum Cosmology · Physics 2021-08-24 Annegret Burtscher , Michael K. -H. Kiessling , A. Shadi Tahvildar-Zadeh

Homogeneous, nearly-isotropic Bianchi cosmological models are considered. Their time evolution is expressed as a complete set of non-interacting linear modes on top of a Friedmann-Robertson-Walker background model. This connects the…

General Relativity and Quantum Cosmology · Physics 2011-09-08 Andrew Pontzen , Anthony Challinor

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmic string is investigated. A nonlinear spinor field is used to simulate the cosmological cloud of strings. It is shown that the spinor field simulation offer…

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

We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI0-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an…

General Relativity and Quantum Cosmology · Physics 2011-08-26 Ozgur Akarsu , Can B. Kilinc

Following up on hints of anisotropy in the cosmic microwave background radiation (CMB) data, we investigate locally rotational symmetric (LRS) Bianchi type I spacetimes with non-minimally coupled scalar fields. To single out potentially…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Y. Kucukakca , U. Camci , İ. Semiz

An LRS Bianchi-I space-time model is studied with constant Hubble parameter in $f(R,T)=R+2\lambda T$ gravity. Although a single (primary) matter source is considered, an additional matter appears due to the coupling between matter and…

General Relativity and Quantum Cosmology · Physics 2021-11-16 Vijay Singh , Aroonkumar Beesham

We study the locally rotational symmetry Bianchi type-I dark energy model in the framework of $f(T)$ theory of gravity, where $T$ denotes the torsion scalar. A viable cosmological model is undertaken and the isotropization of this latter is…

General Relativity and Quantum Cosmology · Physics 2014-01-13 M. E. Rodrigues , I. G. Salako , M. J. S. Houndjo , J. Tossa

In this work, we have discussed a spatially homogeneous and anisotropic Bianchi type-I space-time in the presence of Barrow holographic dark energy (infrared cut-off is the Hubble's horizon) proposed by Barrow recently (Physics Letters B…

General Relativity and Quantum Cosmology · Physics 2023-02-03 M. Koussour , S. H. Shekh , M. Bennai

New dark energy models in anisotropic Bianchi type-I (B-I) space-time with variable EoS parameter and constant deceleration parameter have been investigated in the present paper. The Einstein's field equations have been solved by applying a…

General Physics · Physics 2011-07-15 Anirudh Pradhan , H. Amirhashchi , Bijan Saha

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model…

General Relativity and Quantum Cosmology · Physics 2009-11-13 C. Ortiz , E. Mena-Barboza , M. Sabido , J. Socorro

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

Bianchi type III (BIII) metric is an interesting anisotropic model for studying cosmic anisotropy as it has an additional exponential term multiplied to a directional scale factor. Thus, the cosmological parameters obtained for this BIII…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Pranjal Sarmah , Umananda Dev Goswami