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Related papers: Islands in Bianchi type-I Universe

200 papers

We investigate brane-worlds with a pure magnetic field and a perfect fluid. We extend earlier work to brane-worlds, and find new properties of the Bianchi type I brane-world. We find new asymptotic behaviours on approach to the singularity…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John D. Barrow , Sigbjorn Hervik

The early time behaviour of brane-world models is analysed in the presence of anisotropic stresses. It is shown that that the initial singularity cannot be isotropic, unless there is also an isotropic fluid stiffer than radiation present.…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Sigbjorn Hervik

In this study, we use a single-mode squeezed thermal vacuum state formalism and examine the nature of a massive homogeneous scalar field, minimally coupled to the gravity in the framework of semiclassical gravity in the Bianchi type-I…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Karam Chand

In this paper we investigate expanding Bianchi type I models with two tilted fluids with linear equations of state. Individually the fluids have non-zero energy fluxes w.r.t. the symmetry surfaces, but these cancel each other because of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Patrik Sandin , Claes Uggla

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi

A self-consistent system of interacting nonlinear spinor and scalar fields within the scope of a Bianchi type-I cosmological model filled with perfect fluid is considered. Exact self-consistent solutions to the corresponding field equations…

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

In this article, we propose an anisotropic Bianchi-I type cosmological model in non-conservative Unimodular Gravity ($\mathrm{NUG}$). We show that simply using the Bianchi-I type metric does not resolve a striking characteristic of the…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Marcelo H. Alvarenga , Júlio C. Fabris

We study the anisotropic Bianchi type-I cosmological model at late times, taking into account quantum gravitational corrections in the formalism of the exact renormalization group flow of the effective average action for gravity. The…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Rituparna Mandal , Sunandan Gangopadhyay , Amitabha Lahiri

Loop quantum cosmology leads to a difference equation for the wave function of a universe, which in general has solutions changing rapidly even when the volume changes only slightly. For a semiclassical regime such small-scale oscillations…

General Relativity and Quantum Cosmology · Physics 2009-03-24 Daniel Cartin , Gaurav Khanna , Martin Bojowald

We consider a simple cosmological model consisting of an empty Bianchi I Universe, whose Hamiltonian we deparametrise to provide a natural clock variable. The model thus effectively describes an isotropic universe with an induced clock…

General Relativity and Quantum Cosmology · Physics 2022-01-26 Przemysław Małkiewicz , Patrick Peter , S. D. P. Vitenti

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

Space-times which allow a slicing into homogeneous spatial hypersurfaces generalize the usual Bianchi models. One knows already that in these models the Bianchi type may change with time. Here we show which of the changes really appear. To…

General Relativity and Quantum Cosmology · Physics 2009-10-28 M. Rainer , H. -J. Schmidt

In this note, we point out that in the eternal inflation driven by the metastable vacua of the landscape, it might be possible that some large and local quantum fluctuations with the null energy condition violation can stride over the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yun-Song Piao

Cosmological solutions are obtained in an anisotropic Kantowski-Sachs (KS) and Bianchi Type-I universes considering a cosmological constant with Skyrme fluid. Interestingly, the solutions obtained here in both the KS and Bianchi-I…

General Relativity and Quantum Cosmology · Physics 2022-06-09 Rikpratik Sengupta , B C Paul , Prasenjit Pal

In this paper, we study a Bianchi type -I model of universe filled with barotropic and dark energy(DE) type fluids. The present values of cosmological parameters such as Hubble constant $H_0$, barotropic, DE and anisotropy energy parameters…

General Relativity and Quantum Cosmology · Physics 2021-08-03 G. K. Goswami , Meena Mishra , Anil Kumar Yadav , Anirudh Pradhan

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is considered. The first objective of this study is to investigate Einstein equations using a tractable assumption usually accepted in the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Victor Rikhvitsky , Bijan Saha , Mihai Visinescu

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

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

We study anisotropic Bianchi-I cosmology, incorporating quantum gravitational corrections into the Einstein equation through the scale-dependent Newton coupling and cosmological term, as determined by the flow equation of the effective…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Chiang-Mei Chen , Akihiro Ishibashi , Rituparna Mandal , Nobuyoshi Ohta

In the course of investigation of our present universe by considering the five-dimensional locally rotationally symmetric (LRS) Bianchi type-I universe with time-dependent deceleration parameters in Lyra manifold, it is excitingly found…

General Physics · Physics 2019-02-01 Kangujam Priyokumar Singh , Mahbubur Rahman Mollah