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In this paper, we search the existence of invariant solutions of Bianchi type I space-time in the context of $f\left(R,T\right)$ gravity. The exact solution of the Einstein's field equations are derived by using Lie point symmetry analysis…

General Physics · Physics 2018-02-01 Anil Kumar Yadav , Ahmad T. Ali

We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VI$_{-1/9}$ using dynamical systems methods and numerical simulations. We study models with and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S Hervik , R J van den Hoogen , W C Lim , A A Coley

LRS Bianchi type-I models have been studied in the cosmological theory based on Lyra's geometry. A new class of exact solutions has been obtained by considering a time dependent displacement field for variable deceleration parameter models…

General Relativity and Quantum Cosmology · Physics 2010-05-28 Anirudh Pradhan , D. S. Chauhan

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

Gradient vector fields are fundamental objects from both theoretical and practical perspectives, since various phenomena can be modeled within this framework. The ``moduli space'' of such vector fields provides the foundation for describing…

Dynamical Systems · Mathematics 2025-10-02 Tomoo Yokoyama

In a companion article (referred hearafter as paper I) a detailed study of the simply transitive Spatially Homogeneous (SH) models of class A concerning the existence of a simply transitive similarity group has been given. The present work…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Pantelis S. Apostolopoulos

We consider the dynamics of a Bianchi type I spacetime in the presence of dilaton and magnetic fields. The general solution of the Einstein-Maxwell dilaton field equations can be obtained in an exact parametric form. Depending on the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 T. Harko , M. K. Mak

We use a conformal transformation to find solutions to the generalised scalar-tensor theory, with a coupling constant dependent on a scalar field, in an empty Bianchi type I model. We describe the dynamical behaviour of the metric functions…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Stephane Fay

We consider the problem of picking a physically motivated vacuum state on a spherically symmetric spacetime with an extra conformal Killing vector, as opposed to an extra Killing vector as in the Schwarzschild case. Considering a conformal…

General Relativity and Quantum Cosmology · Physics 2014-03-07 Alex Venditti , Charles Dyer

Einstein's field equations for stationary Bianchi type II models with a perfect fluid source are investigated. The field equations are rewritten as a system of autonomous first order differential equations. Dimensionless variables are…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Ulf S. Nilsson , C. Uggla

A systematic dynamical system approach is applied to study the cosmology of anisotropic Bianchi I universes in which a vector field is assumed to operate on a disformal frame. This study yields a number of new fixed points, among which…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-02 Tomi S. Koivisto , Federico R. Urban

In this paper a class of conformal field theories with nonabelian and discrete group of symmetry is investigated. These theories are realized in terms of free scalar fields starting from the simple $b-c$ systems and scalar fields on…

High Energy Physics - Theory · Physics 2009-10-22 Franco Ferrari

We study integrable models in the Bianchi I metric case with scalar fields minimally and non-minimally coupled with gravity and the correspondence between their general solutions. Using the model with a minimally coupled scalar field and a…

General Relativity and Quantum Cosmology · Physics 2018-01-26 A. Yu. Kamenshchik , E. O. Pozdeeva , A. Tronconi , G. Venturi , S. Yu. Vernov

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 paper we examine different aspects of the geometry of closed conformal vector fields on Riemannian manifolds. We begin by getting obstructions to the existence of closed conformal and nonparallel vector fields on complete manifolds…

Differential Geometry · Mathematics 2010-04-01 A. Caminha

Bianchi modular forms are automorphic forms over an imaginary quadratic field, associated to a Bianchi group. Even though modern studies of Bianchi modular forms go back to the mid 1960's, most of the fundamental problems surrounding their…

Number Theory · Mathematics 2017-03-23 Alexander Rahm , Panagiotis Tsaknias

We initiate quantitative studies of complexity in (1+1)-dimensional conformal field theories with a view that they provide the simplest setting to find a gravity dual to complexity. Our work pursues a geometric understanding of complexity…

High Energy Physics - Theory · Physics 2021-01-28 Mario Flory , Michal P. Heller

In vacuum space-times the exterior derivative of a Killing vector field is a 2-form (named here as the Papapetrou field) that satisfies Maxwell's equations without electromagnetic sources. In this paper, using the algebraic structure of the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Francesc Fayos , Carlos F. Sopuerta

In this paper the dynamics of free gauge fields in Bianchi type I-VII$_{h}$ space-times is investigated. The general equations for a matter sector consisting of a $p$-form field strength ($p\,\in\,\{1,3\}$), a cosmological constant…

General Relativity and Quantum Cosmology · Physics 2018-04-10 Ben David Normann , Sigbjørn Hervik , Angelo Ricciardone , Mikjel Thorsrud

The symmetry classification method is applied to the string-like scalar fields in two-dimensional space-time. When the configurational space is three-dimensional and reducible we present the complete list of the systems admiting higher…

solv-int · Physics 2007-05-23 D. K. Demskoy , A. G. Meshkov
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