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In this work, we study some physical aspects of unitary evolution of Bianchi-I model. In particular, we study the behavior of the volume and the scale factor as a function of time for the Bianchi-I universe with ultra-relativistic fluid…

General Relativity and Quantum Cosmology · Physics 2016-01-28 Sridip Pal

We study the dynamics of the Bianchi I universe in modified loop quantum cosmology (mLQC-I) and uncover a robust mechanism for isotropization: the shear is dynamically suppressed after the bounce and decays rapidly in the quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Wen-Cong Gan , Leila L. Graef , Rudnei O. Ramos , Gustavo S. Vicente , Anzhong Wang

We study the effects of noncommutativity, in the form of a Lie-algebraically deformed Poisson commutation relations, on the evolution of a Bianchi type I cosmological model with a positive cosmological constant. The phase space variables…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Babak Vakili , Nima Khosravi

Fluctuation terms and higher moments of a quantum state imply corrections to the classical equations of motion that may have implications in early-universe cosmology, for instance in the state-dependent form of effective potentials. In…

General Relativity and Quantum Cosmology · Physics 2023-07-10 Martin Bojowald , Freddy Hancock

We consider the introduction of anisotropy in a class of bouncing models of cosmology. The presence of anisotropy often spells doom on bouncing models, since the energy density due to the anisotropic stress outweighs that of other matter…

General Relativity and Quantum Cosmology · Physics 2022-01-27 Karthik Rajeev , Vikramaditya Mondal , Sumanta Chakraborty

Quantum cosmology is traditionally formulated in a minisuperspace setting, implicitly averaging fields over space to obtain homogeneous models. For universal reasons related to the uncertainty principle, quantum corrections then depend on…

General Relativity and Quantum Cosmology · Physics 2019-06-05 Martin Bojowald

We present a phase-space noncommutative version of quantum mechanics and apply this extension to Quantum Cosmology. We motivate this type of noncommutative algebra through the gravitational quantum well (GQW) where the noncommutativity…

High Energy Physics - Theory · Physics 2015-05-13 Catarina Bastos , Orfeu Bertolami , Nuno Dias , Joao Nuno Prata

We investigate diagonal Bianchi-I spacetimes in the presence of viscous fluids by using the shear and the anisotropic pressure components as the basic variables, where the viscosity is driven by the (second-order) causal thermodynamics. A…

General Relativity and Quantum Cosmology · Physics 2017-02-13 Eduardo Bittencourt , Leandro G. Gomes , Renato Klippert

We consider minisuperspace models constituted of Bianchi I geometries with a free massless scalar field. The classical solutions are always singular (with the trivial exception of flat space-time), and always anisotropic once they begin…

General Relativity and Quantum Cosmology · Physics 2009-10-31 N. Pinto-Neto , A. F. Velasco , R. Colistete

We exploit a novel approximation scheme to obtain a new and compact formula for the parameters underlying coherent-state control of the evolution of a pair of entangled two-level systems. It is appropriate for long times and for relatively…

Quantum Physics · Physics 2010-08-24 Muhammed Yonac , Joseph H. Eberly

We use the S\'aez-Ballester theory on anisotropic Bianchi I cosmological model, with barotropic fluid and cosmological constant. We obtain the classical solution by using the Hamilton-Jacobi approach. Also the quantum regime is constructed…

General Relativity and Quantum Cosmology · Physics 2016-08-14 J. Socorro , M. Sabido , M. A. Sánchez G. , M. G. Frías Palos

We carry out an investigation into the possibility of developing a Bohmian interpretation based on the continuous motion of point particles for noncommutative quantum mechanics. The conditions for such an interpretation to be consistent are…

High Energy Physics - Theory · Physics 2009-11-10 G. D. Barbosa , N. Pinto-Neto

We study the quantization of some cosmological models within the theory of N=1 supergravity with a positive cosmological constant. We find, by imposing the supersymmetry and Lorentz constraints, that there are no physical states in the…

General Relativity and Quantum Cosmology · Physics 2011-04-15 A. D. Y. Cheng , P. D. D'Eath , P. R. L. V. Moniz

We present results concerning the nature of the cosmological big bounce(BB) transition within the loop geometry underlying loop quantum cosmology (LQC). Our canonical quantization method is an alternative to the standard LQC. An evolution…

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

We carry out the quantization of the full type I and II Bianchi models following the non-perturbative canonical quantization program. These homogeneous minisuperspaces are completely soluble, i.e., it is possible to obtain the general…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Nenad Manojlovic , Guillermo A. Mena Marugan

On the example of a quantum oscillator the connection of the dynamical coherent state with the phase symmetry breaking and the existence of the nondissipative motion is considered. In multiparticle systems of interacting particles similar…

Quantum Physics · Physics 2024-08-13 Yu. M. Poluektov

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

This paper, based on the interdisciplinary frontiers of quantum electrodynamics, causal set theory, and the AdS/CFT holographic duality, integrates Keppler's zero point field resonance theory, the discrete causal structure and horizon…

General Physics · Physics 2026-04-15 Li Zhanchun , Zhang Renwu

We calculate the power spectrum of cosmological perturbations originated from quantum vacuum fluctuations in bouncing scenarios proposed in Ref.~\cite{chamseddine2014cosmology} in the framework of mimetic cosmology. We show that all…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Idaiane L. Machado , Dêivid R. da Silva , Nelson Pinto-Neto

In the present work, we study the noncommutative version of a quantum cosmology model. The model has a Friedmann-Robertson-Walker geometry, the matter content is a radiative perfect fluid and the spatial sections have positive constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , G. A. Monerat , E. V. Corrêa Silva , C. Neves , L. G. Ferreira Filho