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We investigate the electrodynamic in a Bianchi type I cosmological model. This scenario reveals the possibility that photons, during their traveling, can make quantum interference. This effect is only due to the presence of two different…

General Relativity and Quantum Cosmology · Physics 2015-10-20 G. Fanizza , L. Tedesco

Due to the numerical complexities of studying evolution in an anisotropic quantum spacetime, in comparison to the isotropic models, the physics of loop quantized anisotropic models has remained largely unexplored. In particular, robustness…

General Relativity and Quantum Cosmology · Physics 2017-04-14 Peter Diener , Anton Joe , Miguel Megevand , Parampreet Singh

We study the locally rotational symmetry Bianchi type-I dark energy model in the framework of $f(T)$ theory of gravity, where $T$ denotes the torsion scalar. A viable cosmological model is undertaken and the isotropization of this latter is…

General Relativity and Quantum Cosmology · Physics 2014-01-13 M. E. Rodrigues , I. G. Salako , M. J. S. Houndjo , J. Tossa

We study the classical and quantum evolution of a universe in which the matter source is a massive Dirac spinor field and the universe is described by a Bianchi type I metric. We focus attention on those classical solutions that admit a…

General Relativity and Quantum Cosmology · Physics 2009-11-11 B. Vakili , H. R. Sepangi

We consider the Bianchi I geometry coupled to several species of comoving barotropic perfect fluids with a linear equation of state in the context of general relativity. The solution of the dynamics can be reduced to a quadrature, which can…

General Relativity and Quantum Cosmology · Physics 2024-10-29 David Brizuela , Sara F. Uria

Quantization of arbitrary free scalar fields in spatially homogeneous and isotropic space-times is considered. The quantum representation allowing a unitary evolution for the fields is taken as a requirement for the theory. Studying the…

General Relativity and Quantum Cosmology · Physics 2015-06-02 Sandro D. P. Vitenti

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 illustrate the crucial role played by decoherence (consistency of quantum histories) in extracting consistent quantum probabilities for alternative histories in quantum cosmology. Specifically, within a Wheeler-DeWitt quantization of a…

General Relativity and Quantum Cosmology · Physics 2011-05-26 David A. Craig , Parampreet Singh

We investigate the question of unitarity of evolution between hypersurfaces in quantum field theory in curved spacetime from the perspective of the general boundary formulation. Unitarity thus means unitarity of the quantum operator that…

High Energy Physics - Theory · Physics 2011-08-25 Daniele Colosi , Robert Oeckl

The cosmological singularities of the Bianchi I universe are analyzed in the setting of loop geometry underlying the loop quantum cosmology. We solve the Hamiltonian constraint of the theory and find the Lie algebra of elementary…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Piotr Dzierzak , Wlodzimierz Piechocki

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 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

We consider the dynamics of a Bianchi type I spacetime in the presence of dilaton and magnetic fields. The general solution of the Einstein-Maxwell dilaton field equations can be obtained in an exact parametric form. Depending on the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 T. Harko , M. K. Mak

Some new exact solutions of Einstein's field equations in a spatially homogeneous and anisotropic Bianchi type-V space-time with minimally interaction of perfect fluid and dark energy components have been obtained. To prevail the…

General Physics · Physics 2011-10-06 Anirudh Pradhan , H. Amirhashchi

We obtain a general exact solution of the Einstein field equations for the anisotropic Bianchi type I universes filled with an exponential-potential scalar field and study their dynamics. It is shown, in agreement with previous studies,…

General Relativity and Quantum Cosmology · Physics 2010-11-01 J. M. Aguirregabiria , A. Feinstein , J. Ibanez

The mathematically correct approach to constructing quantum geometrodynamics of a closed universe formulated in Part I is realized on the cosmological Bianchi-IX model with scalar fields. The physical adequacy of the obtained…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. A. Savchenko , T. P. Shestakova , G. M. Vereshkov

The non-diagonal Bianchi models are studied in the loop framework for their classical and quantum formulation. The expressions of the Ashtekar-Barbero-Immirzi variables and their properties are found to provide a loop quantization of these…

General Relativity and Quantum Cosmology · Physics 2023-06-19 Matteo Bruno , Giovanni Montani

The Gowdy cosmologies are vacuum solutions to the Einstein equations which possess two space-like Killing vectors and whose spatial sections are compact. We consider the simplest of these cosmological models: the case where the spatial…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Mercedes Martín-Benito , Guillermo A. Mena Marugán , Edward Wilson-Ewing

In the context of the Loop Quantum Cosmology we have analysed the holonomy correction to the classical evolution of the simplified Bianchi I model in the presence of vector fields. For the Universe dominated by a massive vector field or by…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Michal Artymowski , Zygmunt Lalak

Astronomical observations suggest that the Universe may be anisotropic on the largest scales. In order to model this situation, we develop a new approach to cosmology that allows for large-scale anisotropy to emerge from the growth of…

General Relativity and Quantum Cosmology · Physics 2023-06-26 Theodore Anton , Timothy Clifton