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We consider the cosmological evolution of a flat anisotropic Universe in $f(T)$ gravity in the presence of a perfect fluid. It is shown that the matter content of the Universe has a significant impact of the nature of a cosmological…

General Relativity and Quantum Cosmology · Physics 2021-06-10 Maria A. Skugoreva , Alexey V. Toporensky

We construct general anisotropic cosmological scenarios governed by an $f(R)$ gravitational sector. Focusing then on Kantowski-Sachs geometries in the case of $R^n$-gravity, and modelling the matter content as a perfect fluid, we perform a…

General Relativity and Quantum Cosmology · Physics 2011-08-19 Genly Leon , Emmanuel N. Saridakis

We investigate a simple inhomogeneous anisotropic cosmology (plane symmetric $G_2$ model) filled with a tilted perfect fluid undergoing velocity diffusion on a scalar field. Considered are two types of fluid: dust and radiation. We solve…

General Relativity and Quantum Cosmology · Physics 2014-11-13 Dmitry Shogin , Sigbjorn Hervik

Following recent considerations of a non-zero value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic and…

Astrophysics · Physics 2011-04-15 Paulo Aguiar , Paulo Crawford

Following the recent recognition of a positive value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Paulo Aguiar , Paulo Crawford

We present an anisotropic cosmological model based on a new exact solution of Einstein equations. The matter content consists of an anisotropic scalar field minimally coupled to gravity and of two isotropic perfect fluids that represent…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Saulo Carneiro , Guillermo A. Mena Marugan

We construct a model of a universe filled with a perfect fluid with isotropic particle pressure. The anisotropic plane symmetric Kasner spacetime is used as a seed metric and through a conformal mapping a perfect fluid is generated. The…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Sudan Hansraj , Megandhren Govender , Narenee Mewalal

In this work we consider the Kantowski-Sachs (KS) universe in the framework of varying speed of light theory. We present the general solutions of the gravitational field equations with variable speed of light $c(t)$, gravitational coupling…

General Physics · Physics 2016-06-27 G. S. Khadekar , Arti Ghogre , Saibal Ray

We consider a cosmological model in which the two major fluid components of the Universe, dark energy and dark matter, flow with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid,…

General Relativity and Quantum Cosmology · Physics 2013-07-24 Tiberiu Harko , Francisco S. N. Lobo

The cosmological principle asserts that on sufficiently large scales the Universe is homogeneous and isotropic on spatial slices. To deviate from this principle requires a departure from the FLRW ansatz. In this paper we analyze the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-23 Andrei Constantin , Thomas R. Harvey , Sebastian von Hausegger , Andre Lukas

We consider dynamics of a flat anisotropic Universe filled by a perfect fluid near a cosmological singularity in quadratic gravity. Two possible regimes are described -- the Kasner anisotropic solution and an isotropic "vacuum radiation"…

General Relativity and Quantum Cosmology · Physics 2017-01-04 A. Toporensky , D. Müller

In this manuscript, we investigate the patterns satisfied by the cosmological anisotropy under the hypothesis of the observers being co-moving with a perfect fluid whose induced space sections are homogeneous with vanishing scalar…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Leandro G. Gomes

In this paper we investigate, from the dynamical systems perspective, the evolution of a Kantowski-Sachs metric in a generic class of $f(R)$ models. We present conditions (i. e., differentiability conditions, existence of minima, monotony…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-27 Genly Leon , Armando A. Roque

The Standard Cosmological Model assumes that the Universe is, on average, homogeneous and isotropic for large scales (z>1), but this principle has been questioned from the results about Cosmic Microwave Background. This radiation has…

General Physics · Physics 2016-04-19 Ericsson López , Mario Llerena , Franklin Aldás

We study the GMGHS spacetimes to analyze the evolution of the anisotropy universe, which can be treated as a doubly warped products manifold possessing warping functions (or scale factor) having the Kantowski-Sachs solution which represents…

General Relativity and Quantum Cosmology · Physics 2016-01-12 Jaedong Choi

Within the context of a cosmic space whose energy source is modeled with a perfect fluid, a uniform model of Universe based on a standard FRW cosmology containing decoupled mixed matter sources namely stiff matter and cosmic dust together…

General Relativity and Quantum Cosmology · Physics 2016-09-07 Denisa-Andreea Mihu

In the context of the modified teleparallel $f(T, B)$-theory of gravity, we consider a homogeneous and anisotropic background geometry described by the Kantowski-Sachs line element. We derive the field equations and investigate the…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Genly Leon , Andronikos Paliathanasis

Cosmological solutions are obtained in an anisotropic Kantowski-Sachs (KS) and Bianchi Type-I universes considering a cosmological constant with Skyrme fluid. Interestingly, the solutions obtained here in both the KS and Bianchi-I…

General Relativity and Quantum Cosmology · Physics 2022-06-09 Rikpratik Sengupta , B C Paul , Prasenjit Pal

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

We consider brane Kantowski-Sachs Universe when bulk space is five-dimensional Anti-deSitter space. The corresponding cosmological equations with perfect fluid are written. For several specific choices of relation between energy and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Makarenko , V. V. Obukhov , K. E. Osetrin
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