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Related papers: Spinor field in Bianchi type-$IX$ space-time

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The classification of emergent spinor fields according to modified bilinear covariants is scrutinized, in spacetimes with nontrivial topology, which induce inequivalent spin structures. Extended Clifford algebras, constructed by equipping…

High Energy Physics - Theory · Physics 2024-05-09 J. M. Hoff da Silva , R. da Rocha

We use the vacuum Bianchi I model as an example to investigate the concept of physical evolution in Loop Quantum Cosmology (LQC) in the absence of the massless scalar field which has been used so far in the literature as an internal time.…

General Relativity and Quantum Cosmology · Physics 2009-11-05 Mercedes Martin-Benito , Guillermo A. Mena Marugan , Tomasz Pawlowski

We start with the consideration of the loop effects for light fields with non-zero mass in the expanding Poincar\'e patch of de Sitter space-time. We derive the Dyson-Schwinger equation, which sums up the leading infrared (growing with…

High Energy Physics - Theory · Physics 2024-11-19 E. T. Akhmedov , V. I. Lapushkin , D. I. Sadekov

The Einstein-Maxwell-dilaton field equations are considered for four-dimensional Bianchi type-V and VI$_0$ models. The general solutions have been obtained and their properties have been discussed.

General Relativity and Quantum Cosmology · Physics 2010-11-24 T. Singh , R. Chaubey

We study the dynamics of a timelike vector field which violates Lorentz invariance when the background spacetime is in an accelerating phase in the early universe. It is shown that a timelike vector field is difficult to realize an…

High Energy Physics - Theory · Physics 2015-05-13 Seoktae Koh , Bin Hu

The nature of cosmological solutions for a homogeneous, anisotropic Universe given by a Bianchi type-I (BI) model in the presence of a Cosmological constant $\Lambda$ is investigated by taking into account dissipative process due to…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , V. Rikhvitsky

Dynamical systems methods are used to study the evolution of the Bianchi I model with a scalar field. We show that inclusion of the non-minimal coupling term between the scalar field and the curvature changes evolution of the model compared…

General Relativity and Quantum Cosmology · Physics 2013-10-09 Orest Hrycyna , Marek Szydlowski

We study the dynamical effects in the scale factors due to the scalar $\phi$-field at the early stages of a supposedly anisotropic Universe expansion in connection with the problem of the initial singularity in the scalar-tensor cosmology…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. N. Núñez-Yépez

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

The Bianchi type I cosmological model is brought into a form where the evolution of observables is governed by the unconstrained Hamiltonian that coincides with the Hamiltonian describing the relative motion of particles in the integrable…

General Relativity and Quantum Cosmology · Physics 2009-11-07 A. M. Khvedelidze , D. M. Mladenov

We consider Brans Dicke scalar vector tensor gravity to study an inflationary scenario of the accelerating expansion of the universe for which the anisotropy property occurs. We study both primordial inflation and late inflationary period…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Hossein Ghaffarnejad , Hoda Gholipour

We consider the asymptotic behaviour of spatially homogeneous spacetimes of Bianchi type IX close to the singularity (we also consider some of the other Bianchi types, e. g. Bianchi VIII in the stiff fluid case). The matter content is…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Hans Ringstrom

Here, we have investigated the interaction of Bianchi type I anisotropic cloud string cosmological model universe with electromagnetic field in the context of general relativity. In this paper, the energy momentum tensor is assumed to be…

General Relativity and Quantum Cosmology · Physics 2019-10-21 Kangujam Priyokumar Singh , Mahbubur Rahman Mollah , Rajshekhar Roy Baruah , Meher Daimary

Evolution of primordial fluctuations in a Brans-Dicke type scalar-tensor gravity theory is comprehensively investigated. The harmonic attractor model, in which the scalar field has its harmonic effective potential in the Einstein conformal…

Astrophysics · Physics 2009-11-07 Ryo Nagata , Takeshi Chiba , Naoshi Sugiyama

We derive the metric for a Bianchi type I space-time with energy density that is dominated by that of a perfect fluid with equation of state $p=w\rho$ and whose anisotropy is seeded by a fixed norm spacelike vector field. We solve for the…

General Relativity and Quantum Cosmology · Physics 2008-05-21 Timothy R. Dulaney , Moira I. Gresham

It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic…

High Energy Physics - Theory · Physics 2009-11-11 James E. Lidsey

The Maxwell-covariant particle model is formulated in tensorial extended D=4 space-time (x_mu, z_{mu nu}) parametrized by ten-dimensional coset of D=4 Maxwell group, with added auxiliary Weyl spinors lambda_alpha, y^alpha. We provide the…

High Energy Physics - Theory · Physics 2015-06-11 Sergey Fedoruk , Jerzy Lukierski

A characteristic feature of loop quantization of the isotropic and Bianchi-I spacetimes is the existence of universal bounds on the energy density and the expansion and shear scalars, independent of the matter content. We investigate the…

General Relativity and Quantum Cosmology · Physics 2012-02-09 Brajesh Gupt , Parampreet Singh

In this paper, we investigate Bianchi type-$VI$ cosmological model for the universe filled with dark energy and viscous fluid in the presence of cosmological constant. Also, we show accelerating expansion of the universe by drawing volume…

General Relativity and Quantum Cosmology · Physics 2013-08-29 J. Sadeghi , Ali R. Amani , N. Tahmasbi

The behaviour of magnetic field in anisotropic Bianchi type I cosmological model for bulk viscous distribution is investigated. The distribution consists of an electrically neutral viscous fluid with an infinite electrical conductivity. It…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Anirudh Pradhan , Sanjay Kumar Singh