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In this paper, spatially homogeneous and anisotropic Bianchi type-I cosmological models of Brans-Dicke theory of gravitation are investigated. The model represents accelerating universe at present and is considered to be dominated by dark…

General Physics · Physics 2021-08-02 Umesh Kumar Sharma , Gopi Kant Goswami , Anirudh Pradhan

Here we discuss a topic that comes up more often than expected: A same theory or theoretical model arises in two different presentations which are assumed to be actually different theories so that these are independently developed.…

General Relativity and Quantum Cosmology · Physics 2023-05-16 Israel Quiros , Francisco Antonio Horta-Rangel

In the particular configuration of the scalar field K-essence in the Wheeler-DeWitt quantum equation, for some age in the Bianchi type I anisotropic cosmological model, a fractional differential equation for the scalar field arises…

General Relativity and Quantum Cosmology · Physics 2023-11-09 J. Socorro , J. Juan Rosales , L. Toledo Sesma

We show that it is possible to realize a cosmological bouncing solution in an anisotropic but homogeneous Bianchi-I background in a class of non-local, infinite derivative theories of gravity. We show that the anisotropic shear grows slower…

General Relativity and Quantum Cosmology · Physics 2021-07-20 K. Sravan Kumar , Shubham Maheshwari , Anupam Mazumdar , Jun Peng

We try to solve the dark matter problem in the fit between theory and the Hubble diagram of supernovae by allowing for torsion via Einstein-Cartan's gravity and for anisotropy via the axial Bianchi I metric. Otherwise we are conservative…

General Relativity and Quantum Cosmology · Physics 2016-04-13 Sami R. ZouZou , Andre Tilquin , Thomas Schucker

In this paper, we have constructed dark energy models in an anisotropic Bianchi-V space-time and studied the role of anisotropy in the evolution of dark energy. We have considered anisotropic dark energy fluid with different pressure…

General Physics · Physics 2017-10-25 B. Mishra , Pratik P. Ray , S. K. J. Pacif

The comprehensive formulation for loop quantum cosmology in the spatially flat, isotropic model was recently constructed. In this paper, the methods are extended to the anisotropic Bianchi I cosmology. Both the precursor and the improved…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Dah-Wei Chiou

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

In this paper, we bring together the five-dimensional Saez-Ballester~(SB) scalar-tensor theory [1] and the induced-matter-theory~(IMT) setting [2], to obtain a modified SB theory (MSBT) in four dimensions. Specifically, by using an…

General Relativity and Quantum Cosmology · Physics 2018-02-15 S. M. M. Rasouli , Paulo Vargas Moniz

The anisotropic Bianchi I cosmological model coupled with perfect fluid is quantized in the minisuperspace. The perfect fluid is described by using the Schutz formalism which allows to attribute dynamical degrees of freedom to matter. A…

General Relativity and Quantum Cosmology · Physics 2015-06-25 F. G. Alvarenga , A. B. Batista , J. C. Fabris , S. V. B. Gonçalves

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

The asymptotic behaviour of two classes of scalar field cosmological models are studied using the theory of dynamical systems: general relativistic Bianchi models containing matter and a scalar field with an exponential potential and a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andrew P. Billyard

The Aether Scalar Tensor (AeST) theory is an extension of General Relativity (GR), proposed for addressing galactic and cosmological observations without dark matter.The action for the theory includes a function that can currently only be…

General Relativity and Quantum Cosmology · Physics 2024-12-03 João Luís Rosa , Tom Zlosnik

Some new exact solutions of Einstein's field equations have come forth within the scope of a spatially homogeneous and anisotropic Bianchi type-III space-time filled with barotropic fluid and dark energy by considering a variable…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-20 Hassan Amirhashchi , Anirudh Pradhan , Rekha Jaiswal

We study the homogeneous but anisotropic cosmological models of Bianchi in presence of a massive scalar field using the ADM Hamiltonian formalism. We begin to describe the main steps to find the ADM Hamiltonian of the General Relativity…

General Relativity and Quantum Cosmology · Physics 2014-04-15 Stephane Fay

The cosmic, general analitic solutions of the Brans--Dicke Theory for the flat space of homogeneous and isotropic models containing perfect, barotropic, fluids are seen to belong to a wider class of solutions --which includes cosmological…

General Relativity and Quantum Cosmology · Physics 2016-08-31 P. Chauvet , J. L. Cervantes-Cota

The anisotropic Bianchi I cosmological model coupled with perfect fluid is quantized in the minisuperspace. The perfect fluid is described by using the Schutz formalism which allows to attribute dynamical degrees of freedom to matter. It is…

General Relativity and Quantum Cosmology · Physics 2007-05-23 F. G. Alvarenga , A. B. Batista , J. C. Fabris , S. V. B. Goncalves

We provide a quantum picture for the emergence of a bouncing cosmology, according to the idea that a semiclassical behavior of the Universe towards the singularity is not available in many relevant Minisuperspace models. In particular, we…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Eleonora Giovannetti , Giovanni Montani

Within the scope of an anisotropic Bianchi type-V cosmological model we have studied the evolution of the universe. The assumption of a diagonal energy-momentum tensor leads to some severe restriction on the metric functions, which on its…

General Physics · Physics 2015-05-01 Bijan Saha

We introduce a new matter action principle, with a wide range of applicability, for the Vlasov equation in terms of a conjugate pair of functions. Here we apply this action principle to the study of matter in Bianchi cosmological models in…

General Relativity and Quantum Cosmology · Physics 2011-08-08 Takahide Okabe , P. J. Morrison , J. E. Friedrichsen , L. C. Shepley