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Related papers: The Bianchi IX Attractor in Modified Gravity

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By using Bianchi I type of homogenous and anisotropic background metric having cylindrical symmetry in $x$ direction of a local cartesian coordinates system, we solve metric field equations for a non-minimally coupled Einstein-Maxwell…

General Relativity and Quantum Cosmology · Physics 2020-12-08 Hossein Ghaffarnejad , Hoda Gholipour

In this paper, we investigate anisotropic cosmological solutions within the framework of Born-Infeld-f(R) gravity, a modification of general relativity that incorporates higher-order curvature invariants. Specifically, we focus on the…

General Relativity and Quantum Cosmology · Physics 2025-01-06 Salih Kibaroğlu

We consider some aspects of the global evolution problem of Hamiltonian homogeneous, anisotropic cosmologies derived from a purely quadratic action functional of the scalar curvature. We show that models can isotropize in the positive…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Spiros Cotsakis , George Flessas , Peter Leach , Laurent Querella

This paper is devoted to investigate the exact solutions of Bianchi type $I$ spacetime in the context of $f(R,T)$ gravity [1], where $f(R,T)$ is an arbitrary function of Ricci scalar $R$ and trace of the energy momentum tensor $T$. For this…

General Relativity and Quantum Cosmology · Physics 2015-06-30 M. Farasat Shamir

Diagonal Bianchi type-IX models are studied in the quantum theory of $ N = 1 $ supergravity with a cosmological constant. It is shown, by imposing the supersymmetry and Lorentz quantum constraints, that there are no physical quantum states…

General Relativity and Quantum Cosmology · Physics 2009-10-22 A. D. Y. Cheng , P. D. D'Eath , P. R. L. V. Moniz

Following our previous papers concerning the quantization of the vacuum Bianchi-IX model within or beyond the Born-Oppenheimer and adiabatic approximation, we develop a more elaborate analysis of the dynamical properties of the model based…

General Relativity and Quantum Cosmology · Physics 2016-04-11 Hervé Bergeron , Ewa Czuchry , Jean-Pierre Gazeau , Przemysław Małkiewicz

We investigate a corner of the Bianchi models that has not received much attention: "extended FLRW models" (eFLRW) defined as a cosmological model with underlying anisotropic Bianchi geometry that nevertheless expands isotropically and can…

General Relativity and Quantum Cosmology · Physics 2020-02-21 Mikjel Thorsrud , Ben D. Normann , Thiago S. Pereira

The present study deals with spatial homogeneous and anisotropic locally rotationally symmetric (LRS) Bianchi-II dark energy model in general relativity. The Einstein's field equations have been solved exactly by taking into account the…

General Physics · Physics 2012-09-26 Bijan Saha , Anil Kumar Yadav

We obtain all homogeneous solutions of new massive gravity models on S^3 and AdS_3 by extending previously known results for the cosmological topologically massive theory of gravity in three dimensions. In all cases, apart from the…

High Energy Physics - Theory · Physics 2010-12-15 Ioannis Bakas , Christos Sourdis

We review the solution space for the field equations of Einstein's General Relativity for various static, spherically symmetric spacetimes. We consider the vacuum case, represented by the Schwarzschild black hole; the de…

General Relativity and Quantum Cosmology · Physics 2024-10-02 Andronikos Paliathanasis

We present a simple model which generates cosmological anisotropies on top of standard FLRW geometry. This is in some sense reminiscent of the mean field approximation, where the mean field cosmological model under consideration would be…

General Relativity and Quantum Cosmology · Physics 2024-09-25 Bum-Hoon Lee , Hochoel Lee , Wonwoo Lee , Nils A. Nilsson , Somyadip Thakur

In this paper, we describe the dynamics of a Bianchi Type V vacuum universe with an arbitrary cosmological constant. We begin by using an orthonormal frame approach to write Einstein's field equations as a coupled system of first-order…

General Relativity and Quantum Cosmology · Physics 2017-04-12 Ikjyot Singh Kohli

We obtain an infinite number of exact static, Ricci-flat spherically symmetric vacuum solutions for a class of f(R) theories of gravity. We analytically derive two exact vacuum black-hole solutions for the same class of f(R) theories. The…

General Relativity and Quantum Cosmology · Physics 2020-10-02 Semin Xavier , Jose Mathew , S. Shankaranarayanan

In this paper, we consider spatially homogenous and anisotropic Bianchi type I universe in the context of F(T) gravity. We construct some corresponding models using conservation equation and equation of state parameter representing…

General Relativity and Quantum Cosmology · Physics 2015-05-28 M. Sharif , Shamaila Rani

This manuscript is devoted to investigate Bianchi Type $I$ universe in the context of $f(R,T)$ gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type $I$ spacetime. The modified field…

General Physics · Physics 2015-08-07 M. Farasat Shamir

In this paper, we would like to figure out whether a k-inflation model admits the Bianchi type I metric as its inflationary solution under a constant-roll condition in the presence of the supergravity motivated coupling between scalar and…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Duy H. Nguyen , Tuyen M. Pham , Thien D. Le , Tuan Q. Do

We try to find the possibility of a Bianchi V universe in the modified gravitational field theory of $f(R,T)$. We have considered a Lagrangian model in the connection between the trace of the energy-momentum tensor $T$ and the Ricci scalar…

General Relativity and Quantum Cosmology · Physics 2025-11-24 Lokesh Kumar Sharma , Suresh Parekh , Saibal Ray , Anil Kumar Yadav

A plane symmetric Bianchi-I model is explored in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor. The solutions are obtained with the consideration of a specific Hubble parameter which yields a…

General Relativity and Quantum Cosmology · Physics 2020-03-23 Vijay Singh , Aroonkumar Beesham

We study the attractor mechanism for N=1 supergravity coupled to vector and chiral multiplets and compute the attractor equations of these theories. These equations may have solutions depending on the choice of the holomorphic symmetric…

High Energy Physics - Theory · Physics 2008-11-26 Laura Andrianopoli , Riccardo D'Auria , Sergio Ferrara , Mario Trigiante

We study the anisotropic Bianchi I and Bianchi II models in vacuum in the framework of deformed commutation relations (DCRs). Working in a parametrisation of the spatial metric by a volume and two anisotropy variables, we propose modified…

General Relativity and Quantum Cosmology · Physics 2025-10-29 Gabriele Barca , Steffen Gielen