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Related papers: Non Commutative Bianchi type II Quantum Cosmology

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We find solutions for quantum Class A Bianchi models of the form $\rm \Psi=W e^{\pm \Phi}$ generalizing the results obtained by Moncrief and Ryan in standard quantum cosmology. For the II and IX Bianchi models there are other solutions $\rm…

General Relativity and Quantum Cosmology · Physics 2009-10-28 O. Obregón , J. Socorro

In this paper we study the exact solutions for a viscous fluid distribution in Bianchi II, VIII, and IX models. The metric is simplified by assuming a relationship between the coefficients and the metric tensor. Solutions are obtained in…

General Relativity and Quantum Cosmology · Physics 2021-05-25 A. Banerjee , Abhik Kumar Sanyal , S. Chakraborty

The present work shows that a properly chosen ordering of operators can restore unitarity in anisotropic quantum cosmological models. Bianch V and Bianchi IX models with a perfect fluid are worked out. It has been shown that a…

General Relativity and Quantum Cosmology · Physics 2015-02-27 Sridip Pal , Narayan Banerjee

We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

In this paper, we study in detail a perfect fluid cosmological model with time-varying "constants" using dimensional analysis and the symmetry method. We examine the case of variable "constants" in detail without considering the perfect…

General Relativity and Quantum Cosmology · Physics 2009-12-30 José Antonio Belinchón , Indrajit Chakrabarty

The present study deals with spatially homogeneous and anisotropic Bianchi-I cosmological model representing massive strings. The energy-momentum tensor, as formulated by Letelier (Phys. Rev. D 28: 2414, 1983) has been used to construct…

General Physics · Physics 2014-03-11 Chanchal Chawla , R. K. Mishra , Anirudh Pradhan

D-dimensional cosmological model describing the evolution of a multicomponent perfect fluid with variable barotropic parameters in n Ricci-flat spaces is investigated. The equations of motion are integrated for the case, when each component…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. -M. Alimi , V. R. Gavrilov , V. N. Melnikov

We investigate a new class of LRS Bianchi type-II cosmological models by revisiting in the paper of Mishra {\it et al} (2013) by considering a new deceleration parameter (DP) depending on the time in string cosmology for the modified…

General Physics · Physics 2021-08-02 Archana Dixit , Rashid Zia , Anirudh Pradhan

It was shown recently that a very simple nonlocal de Sitter gravity model contains exact vacuum cosmological solution which mimics dark energy and dark matter in flat space. Some other interesting solutions have been also found. In this…

General Relativity and Quantum Cosmology · Physics 2023-07-04 Ivan Dimitrijevic

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

The perfect fluid cosmology in the 1+d+D dimensional Kaluza-Klein spacetimes for an arbitrary barotropic equation of state $p= n \rho$ is quantized by using the Schutz's variational formalism. We make efforts in the mathematics to solve the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Wung-Hong Huang , I-Chin Wang

Semi-classical states for the Wheeler-DeWitt equation of a Bianchi type I model in the presence of a scalar field are analyzed. It is outlined how this scheme can effectively describe more general situations, where the curvature of the…

General Relativity and Quantum Cosmology · Physics 2010-12-23 Francesco Cianfrani , Giovanni Montani , Marco Muccino

The asymptotic properties of the Bianchi type II cosmological model in the Brane-world scenario are investigated. The matter content is assumed to be a combination of a perfect fluid and a minimimally coupled scalar field that is restricted…

General Relativity and Quantum Cosmology · Physics 2009-11-07 R. J. van den Hoogen , J. Ibanez

We present a Friedmann-Robertson-Walker (FRW) quantum cosmological model within the framework of Finslerian geometry. In this work, we consider a specific fluid. We obtain the corresponding Wheeler-DeWitt equation as the usual constraint…

General Physics · Physics 2019-11-04 S S De , Farook Rahaman , Nupur Paul

Cosmological models of Bianchi type V and I containing a perfect fluid with a linear equation of state plus cosmological constant are investigated using a tetrad approach where our variables are the Riemann tensor, the Ricci rotation…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Michael Bradley , Daniel Eriksson

The minisuperspace model of a Bianchi Type I universe with compact spatial sections is investigated. The classical solutions are brought onto a form were the difference between compact and infinite spatial sections are manifest. One of the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Sigbjorn Hervik

Various models are under consideration with metric type flat FRW whose energy-momentum tensor is described by a perfect fluid whose generic equation state and taking into account the conservation principle, but considering some of the…

General Physics · Physics 2007-05-23 J. A. Belinchon

In this paper we study the cosmological constant emerging from the Wheeler-DeWitt equation as an eigenvalue of the related Sturm-Liouville problem. We employ Gaussian trial functionals and we perform a mode decomposition to extract the…

General Relativity and Quantum Cosmology · Physics 2011-03-22 Remo Garattini , Piero Nicolini

We can solve the Wheeler-DeWitt equation of the enlarged Bianchi I as inhomogeneous type universe with static restriction which had been derived by previous paper. We consider the commutation relation between the static restriction and the…

General Relativity and Quantum Cosmology · Physics 2008-11-28 Shintaro Sawayama

We investigate the Wheeler-DeWitt equation for a flat, homogeneous, and isotropic Universe containing a canonical scalar field with a potential. We show that under the constraint $|\Psi|=1$, where the Wheeler-DeWitt equation exactly becomes…

High Energy Physics - Theory · Physics 2026-04-30 Naoto Maki , Chia-Min Lin , Kazunori Kohri