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In this paper, we consider spatially homogenous and anisotropic Bianchi type I universe in the context of F(T) gravity. We construct some corresponding models using conservation equation and equation of state parameter representing…

General Relativity and Quantum Cosmology · Physics 2015-05-28 M. Sharif , Shamaila Rani

In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…

High Energy Physics - Theory · Physics 2008-11-26 Edmund J. Copeland , M. Sami , Shinji Tsujikawa

We study the dynamics of dark energy in the presence of a 2-form field coupled to a canonical scalar field $\phi$. We consider the coupling proportional to $e^{-\mu \phi/M_{\rm pl}} H_{\alpha \beta \gamma}H^{\alpha \beta \gamma}$ and the…

High Energy Physics - Theory · Physics 2019-09-25 Juan P. Beltrán Almeida , Alejandro Guarnizo , Ryotaro Kase , Shinji Tsujikawa , César A. Valenzuela-Toledo

A model of compact object coupled to inhomogeneous anisotropic dark energy is studied. It is assumed a variable dark energy that suffers a phase transition at a critical density. The anisotropic Lambda-Tolman-Oppenheimer-Volkoff equations…

General Relativity and Quantum Cosmology · Physics 2011-05-12 Cristian R. Ghezzi

Using the ADM formalism in the minisuperspace, we obtain the commutative and noncommutative exact classical solutions and exact wave function to the Wheeler-DeWitt equation with an arbitrary factor ordering, for the anisotropic Bianchi type…

General Relativity and Quantum Cosmology · Physics 2015-05-14 J. Socorro , Luis O. Pimentel , C. Ortiz , M. Aguero

We consider a 5-dimensional Ricci flat bouncing cosmological model in which the 4-dimensional induced matter contains two components at late times - the cold dark matter (CDM)+baryons and dark energy. We find that the arbitrary function…

Astrophysics · Physics 2009-11-13 Lixin Xu , Hongya Liu

An anisotropic Bianchi type I cosmological model with power-law scalar-field potentials of the form $V(\psi_1,\psi_2)=V_1\psi_1^{\pm\lambda_1}+V_2\psi_2^{\pm\lambda_2}$ is studied within a generalized S\'aez--Ballester--K-essence-like…

General Relativity and Quantum Cosmology · Physics 2026-04-14 J. Socorro , A. Gil-Ocaranza , Juan Luis Pérez

We have shown that the phenomenological models with a cosmological constant of the type $\Lambda=\beta(\frac{\ddot R}{R})$ and $\Lambda=3\alpha H^2$, where $R$ is the scale factor of the universe and $H$ is the Hubble constant, are…

Astrophysics · Physics 2007-05-23 Arbab I. Arbab

We present cosmological perturbation theory in neutrino probe interacting dark-energy models, and calculate cosmic microwave background anisotropies and matter power spectrum. In these models, the evolution of the mass of neutrinos is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yong-Yeon Keum

In this paper, we have investigated some features of anisotropic accelerating Bianchi type-I cosmological model in the presence of two non-interacting fluids, i.e. one usual string and other dark energy fluid towards the gravitational field…

General Physics · Physics 2020-04-20 S. H. Shekh , V. R. Chirde

This article discusses a dark energy cosmological model in the standard theory of gravity - general relativity with a broad scalar field as a source. Exact solutions of Einstein's field equations are derived by considering a particular form…

General Relativity and Quantum Cosmology · Physics 2022-08-23 S. K. J. Pacif , Simran Arora , P. K. Sahoo

We present an exact solution of Einstein equations that describes a Bianchi type III spacetime with conformal expansion. The matter content is given by an anisotropic scalar field and two perfect fluids representing dust and isotropic…

General Relativity and Quantum Cosmology · Physics 2013-11-11 Saulo Carneiro , Guillermo A. Mena Marugan

Friedmans cosmological equations for the scale factor are analyzed for the Universe containing dark energy. The parameter of the equation of state of the dark energy is treated as an arbitrary constant whose value lies within the interval…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-13 M. V. Sazhin , O. S. Sazhina , U. Chadayammuri

In this paper, we study a Bianchi type -I model of universe filled with barotropic and dark energy(DE) type fluids. The present values of cosmological parameters such as Hubble constant $H_0$, barotropic, DE and anisotropy energy parameters…

General Relativity and Quantum Cosmology · Physics 2021-08-03 G. K. Goswami , Meena Mishra , Anil Kumar Yadav , Anirudh Pradhan

We consider late-time cosmology in a (phantom) scalar-tensor theory with an exponential potential, as a dark energy model with equation of state parameter close to -1 (a bit above or below this value). Scalar (and also other kinds of)…

High Energy Physics - Theory · Physics 2009-09-17 Emilio Elizalde , Shin'ichi Nojiri , Sergei D. Odintsov

We investigate the structure and radial oscillations of anisotropic compact stars composed of dark energy, using the vanishing complexity factor formalism within general relativity. This novel approach establishes a direct link between the…

General Relativity and Quantum Cosmology · Physics 2024-07-25 G. Panotopoulos , A. Rincon , I. Lopes

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \omega…

Astrophysics · Physics 2009-11-13 Joan Sola , Hrvoje Stefancic

Stability, dark energy (DE) parameterization and swampland aspects for the Bianchi form-$VI_{h}$ universe have been formulated in an extended gravity hypothesis. Here we have assumed a minimally coupled geometry field with a rescaled…

General Physics · Physics 2021-08-03 Archana Dixit , Anirudh Pradhan

Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by incorporating `dark energy', of which the…

Astrophysics · Physics 2010-03-26 Luke Barnes , Matthew J. Francis , Geraint F. Lewis , Eric V. Linder

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

General Relativity and Quantum Cosmology · Physics 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray