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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

In recent years, there have been increasing challenges to the cosmological principle, based on new observations of e.g. supernovae and the cosmic bulk flow. As a result, the cosmological community is speaking their concern for the…

General Relativity and Quantum Cosmology · Physics 2026-05-15 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

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

The behavior near the initial singular state of the anisotropy parameter of the arbitrary type, homogeneous and anisotropic Bianchi models is considered in the framework of the brane world cosmological models. The matter content on the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 T. Harko , M. K. Mak

The improved dynamics of loop quantum cosmology is extended to include the Bianchi type II model. Because these space-times admit both anisotropies and non-zero spatial curvature, certain technical difficulties arise over and above those…

General Relativity and Quantum Cosmology · Physics 2010-01-07 Abhay Ashtekar , Edward Wilson-Ewing

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 spatially homogeneous and anisotropic Bianchi Type I universe has been studied with {\omega} <-1 without Big Smash. It is demonstrated that if cosmic dark energy behaves like a fluid with equation of state p = {\omega}{\rho} (p and {\rho}…

General Relativity and Quantum Cosmology · Physics 2011-08-04 Anil Kumar Yadav

The irrotational Bianchi V cosmological model under the influence of both shear and bulk viscosity, together with heat flux, has been studied. Exact solutions for the model are obtained with three physically viable assumptions. The first…

General Relativity and Quantum Cosmology · Physics 2019-12-09 A. Banerjee , Abhik Kumar Sanyal

Bianchi cosmologies are ``natural'' anisotropic extensions of the Friedmann universes and they have long been used to investigate the cosmological implications of anisotropy. The latter introduces new ingredients to the standard scenarios,…

General Relativity and Quantum Cosmology · Physics 2024-09-13 Amalia Tzartinoglou , Christos G. Tsagas

In this work we construct an effective four-dimensional model by compactifying a ten-dimensional theory of gravity coupled with a real scalar dilaton field on a time-dependent torus. The corresponding action in four dimensions is similar to…

General Relativity and Quantum Cosmology · Physics 2018-04-03 J. Socorro , L. Toledo Sesma , Luis O. Pimentel

This paper investigates the energy bounds in modified Gauss-Bonnet gravity with anisotropic background. Locally rotationally symmetric Bianchi type ${I}$ cosmological model in $f(R,G)$ gravity is considered to meet this aim. Primarily, a…

General Physics · Physics 2017-12-07 M. Farasat Shamir , Ayesha Komal

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

A cosmological description of the universe is proposed in the context of Hamiltonian formulation of a Bianchi IX cosmology minimally coupled to a massless scalar field. The classical and quantum results are studied with special attention to…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Hossein Farajollahi , Arvin Ravanpak

If the dark energy equation of state is anisotropic, the expansion rate of the universe becomes direction-dependent at late times. We show that such models are not only cosmologically viable but that they could explain some of the observed…

Astrophysics · Physics 2010-11-11 Tomi Koivisto , David F. Mota

The present work is devoted to investigate the Noether symmetries of the locally rotationally symmetric Bianchi type I space time in $f(T,B)$ gravity theory which depends on the torsion scalar $T$ and the boundary term $B$. In this theory,…

General Relativity and Quantum Cosmology · Physics 2018-07-16 Yusuf Kucukakca

We generalize the predictions for the CMB anisotropy patterns arising in Bianchi type VIIh universes to include a dark energy component. We consider these models in light of the result of Jaffe et al. (2005a,b) in which a correlation was…

Astrophysics · Physics 2009-11-13 T. R. Jaffe , S. Hervik , A. J. Banday , K. M. Gorski

In this work a new non-minimally coupled model is presented, where a generic function $f(R)$ of the scalar curvature factors the usual Einstein-Hilbert action functional, motivated by relevant results obtained from similar models. Its…

General Relativity and Quantum Cosmology · Physics 2016-11-22 R. P. L. Azevedo , J. Páramos

Within the scope of Bianchi type-VI cosmological model we study the role of spinor field in the evolution of the Universe. It is found that due to the spinor affine connections the energy-momentum tensor of the spinor field possesses…

General Relativity and Quantum Cosmology · Physics 2016-05-24 Bijan Saha

A spatially homogeneous and anisotropic Bianchi type I universe is studied with the interacting holographic and new agegraphic scalar fields models of dark energy. Given, the framework of the anisotropic model, both the dynamics and…

General Relativity and Quantum Cosmology · Physics 2018-08-10 Hossien Hossienkhani , Ali Aghamohammadi , S. W. Rabieei , abdollah Refaei

The Poincar\'e gauge theory of gravity has a metric compatible connection with independent dynamics that is reflected in the torsion and curvature. The theory allows two good propagating spin-0 modes. Dynamical investigations using a simple…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Fei-Hung Ho , James M. Nester
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