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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 study the effects of a spatially homogenous magnetic field in Bianchi-I cosmological models. The cases of a pure magnetic field and two models with additional dust and a massless scalar field (stiff matter) are also considered. At the…

General Relativity and Quantum Cosmology · Physics 2023-10-31 Roberto Casadio , Alexander Kamenshchik , Panagiotis Mavrogiannis , Polina Petriakova

The paper presents some exact solutions of Bianchi types I, III and Kantowski-Sachs cosmological models consisting of a dissipative fluid along with an axial magnetic field. A barytropic equation of state between the thermodynamic pressure…

General Relativity and Quantum Cosmology · Physics 2021-05-18 A. Banerjee , Abhik Kumar Sanyal

An anisotropic cosmological model with a gauge field, presented by spatially homogeneous SU(2)-symmetric Yang-Mills potentials, is considered. Bianchi-I model with axial symmetry is analyzed; a new exact solution, which describes the early…

General Relativity and Quantum Cosmology · Physics 2025-05-06 Alexander B. Balakin , Gleb B. Kiselev

A recent quasiclassical description of a tunneling universe model is shown to exhibit chaotic dynamics by an analysis of fractal dimensions in the plane of initial values. This result relies on non-adiabatic features of the quantum…

General Relativity and Quantum Cosmology · Physics 2023-11-15 Martin Bojowald , Ari Gluckman

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

Brane-world models provide a phenomenology that allows us to explore the cosmological consequences of some M theory ideas, and at the same time to use precision cosmology as a test of these ideas. In order to achieve this, we need to…

Astrophysics · Physics 2007-05-23 Roy Maartens

We study the Bianchi-I cosmological model motivated by signals of statistical isotropy violation seen in cosmic microwave background (CMB) observations and others. To that end, we consider various kinds of anisotropic matter that source…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Anshul Verma , Sanjeet K. Patel , Pavan K. Aluri , Sukanta Panda , David F. Mota

In this work, we study the effect of a magnetic field on the growth of cosmological perturbations. We develop a mathematical consistent treatment in which a perfect fluid and a uniform magnetic field evolve together in a Bianchi I universe.…

General Relativity and Quantum Cosmology · Physics 2019-11-19 Federico Di Gioia , Giovanni Montani

The Bianchi IX cosmological model is analyzed in a generalized uncertainty principle framework. The Arnowitt-Deser-Misner reduction of the dynamics is performed and a time-coordinate, namely the volume of the Universe, naturally arises.…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Marco Valerio Battisti , Giovanni Montani

In the present work we show that the widely believed pathology of the non-unitarity of anisotropic quantum cosmological models cannot be a generic problem. We exhibit a non trivial example, a Bianchi-I model with an ultrarelativistic fluid,…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Sridip Pal , Narayan Banerjee

Using a metric-based formalism to treat cosmological perturbations, we discuss the connection between anisotropic stress on the brane and brane bending. First we discuss gauge-transformations, and draw our attention to gauges, in which the…

High Energy Physics - Theory · Physics 2009-10-31 M. Dorca , C. van de Bruck

In the context of the Randall-Sundrum braneworld, an exhaustive and detailed description of the approach based in the minimal anisotropic consequence onto the brane, which has been successfully used to generate exact interior solutions to…

General Relativity and Quantum Cosmology · Physics 2017-08-23 J Ovalle

We consider the dynamics of a causal bulk viscous cosmological fluid filled constantly decelerating Bianchi type I space-time. The matter component of the Universe is assumed to satisfy a linear barotropic equation of state and the state…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , T. Harko

A new cosmological solution of the gravitational field equations in the generalized Randall-Sundrum model for an anisotropic brane with Bianchi I geometry and with perfect fluid as matter sources is presented. The matter is described by a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Bikash Chandra Paul

The specific behavior of spinor field in curve space-time with the exception of FRW model almost always gives rise to non-trivial non-diagonal components of the energy-momentum tensor. This non-triviality of non-diagonal components of the…

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

The truncated Israel-Stewart theory of irreversible thermodynamics is used to describe the bulk viscous pressure and the anisotropic stress in a class of spatially homogeneous viscous fluid cosmological models. The governing system of…

General Relativity and Quantum Cosmology · Physics 2010-04-06 R. J. van den Hoogen , A. A. Coley

Self-consistent solutions to the spinor, scalar and BI gravitational field equations are obtained. The problems of initial singularity and asymptotically isotropization process of the initially anisotropic space-time are studied. It is also…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bijan Saha

A geometric theory of brane-worlds with large or non-compact extra dimensions is presented. It is shown that coordinate gauge independent perturbations of the brane-world correspond to the Einstein-Hilbert dynamics derived from the…

High Energy Physics - Theory · Physics 2007-05-23 M. D. Maia , E. M. Monte

In loop quantum cosmology, ambiguities in the Hamiltonian constraint can result in models with varying phenomenological predictions. In the homogeneous isotropic models, these ambiguities were settled, and the improved dynamics was found to…

General Relativity and Quantum Cosmology · Physics 2023-11-16 Meysam Motaharfar , Parampreet Singh , Eklavya Thareja
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