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In this paper we derive some new invariant solutions of Einstein-Maxwell's field equations for string fluid as source of matter in cylindrically symmetric space-time with Variable Magnetic Permeability. We also discuss the physical and…

General Relativity and Quantum Cosmology · Physics 2015-01-09 Ahmad T. Ali , Anil Kumar Yadav , Farook Rahaman , Arkopriya Mallick

A new class of solutions of Einstein field equations has been investigated for inhomogeneous cylindrically symmetric space-time with string source. To get the deterministic solution, it has been assumed that the expansion ($\theta$) in the…

General Relativity and Quantum Cosmology · Physics 2014-05-06 Anirudh Pradhan , A. K. Yadav , R. P. Singh , V. K. Singh

In this paper, we have searched the existence of the similarity solution for plane symmetric inhomogeneous cosmological models in general relativity. The matter source consists of perfect fluid with proportionality relation between…

General Relativity and Quantum Cosmology · Physics 2014-07-14 Ahmad T. Ali , Anil Kumar Yadav

A new class of cylindrically symmetric inhomogeneous string cosmological models is investigated. To get the deterministic solution, it has been assumed that the expansion ($\theta$) in the model is proportional to the eigen value…

General Relativity and Quantum Cosmology · Physics 2018-07-10 Anirudh Pradhan , Mukesh Kumar Mishra , Anil Kumar Yadav

Based upon the intrinsic symmetries approach to inhomogeneous cosmologies, we propose an exact solution to Einstein's field equations where the spatial sections are flat and the source is a non-perfect fluid such that the dissipative terms…

General Relativity and Quantum Cosmology · Physics 2021-03-11 E. Bittencourt , L. G. Gomes , G. B. Santos

Cylindrically symmetric inhomogeneous string cosmological models in presence of electromagnetic field is investigated. We have assumed that $F_{12}$ is the only non-vanishing component of $F_{ij}$. The Maxwell's equations require that…

General Relativity and Quantum Cosmology · Physics 2014-05-06 Anirudh Pradhan , Anju Rai , Raj Bali

Global symmetries of the string effective action are employed to generate tilted, homogeneous Bianchi type VI_h string cosmologies from a previously known stiff perfect fluid solution to Einstein gravity. The dilaton field is not constant…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Dominic Clancy , Alexander Feinstein , James E. Lidsey , Reza Tavakol

We present two classes of inhomogeneous, spherically symmetric solutions of the Einstein-Maxwell-Perfect Fluid field equations with cosmological constant generalizing the Vaidya-Shah solution. Some special limits of our solution reduce to…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Metin Gurses , Yaghoub Heydarzade

We present exact inhomogeneous and anisotropic cosmological solutions of low-energy string theory containing dilaton and axion fields. The spacetime metric possesses cylindrical symmetry. The solutions describe ever-expanding universes with…

High Energy Physics - Theory · Physics 2009-10-30 John D. Barrow , Kerstin E. Kunze

In this talk we show a stiff fluid solution of the Einstein equations for a cylindrically symmetric spacetime. The main features of this metric are that it is non-separable in comoving coordinates for the congruence of the worldlineS of the…

General Relativity and Quantum Cosmology · Physics 2009-06-01 L. Fernández-Jambrina

Families of anisotropic and inhomogeneous string cosmologies containing non-trivial dilaton and axion fields are derived by applying the global symmetries of the string effective action to a generalized Einstein-Rosen metric. The models…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Dominic Clancy , Alexander Feinstein , James E. Lidsey , Reza Tavakol

The plane-symmetric inhomogeneous cosmological models of perfect fluid distribution with electro-magnetic field is obtained in the framework of Lyra's geometry. To get the deterministic solution, I have considered $ A=f(x)\nu(t) $, $…

General Relativity and Quantum Cosmology · Physics 2010-06-01 Anil Kumar Yadav

In this paper we investigate a class of solutions of Einstein equations for the plane-symmetric perfect fluid case with shear and vanishing acceleration. If these solutions have shear, they must necessarily be non-static. We examine the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Purnima Pandey , Sunil Kumar Singh

We determine the most general form of the antisymmetric $H$-field tensor derived from a purely time-dependent potential that is admitted by all possible spatially homogeneous cosmological models in 3+1-dimensional low-energy bosonic string…

High Energy Physics - Theory · Physics 2009-10-30 John D. Barrow , Kerstin E. Kunze

In this work, we obtained exact solutions of Einstein's field equations for plane symmetric cosmological models by assuming that thy admit conformal motion. The space-time geometry of these solutions is found to be nonsingular, non-vacuum…

General Relativity and Quantum Cosmology · Physics 2025-01-07 Ragab M. Gad , Awatif Al-Jedani , Shahad T. Alsulami

We present solution generating techniques which permit to construct exact inhomogeneous and anisotropic cosmological solutions to a four-dimensional low energy limit of string theory containing non-minimally interacting electromagnetic and…

High Energy Physics - Theory · Physics 2009-10-31 Stoytcho Yazadjiev

Einstein's field equations for spatially self-similar spherically symmetric perfect-fluid models are investigated. The field equations are rewritten as a first-order system of autonomous differential equations. Dimensionless variables are…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Martin Goliath , Ulf S Nilsson , Claes Uggla

We investigate solutions of Einstein field equations for the non-static spherically symmetric perfect fluid case using different equations of state. The properties of an exact spherically symmetric perfect fluid solutions are obtained which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Sharif , T. Iqbal

In this paper we present a class of exact inhomogeneous solutions to Einstein's equations for higher dimensional Szekeres metric with perfect fluid and a cosmological constant. We also show particular solutions depending on the choices of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Subenoy Chakraborty , Ujjal Debnath

We present new exact inhomogeneous vacuum cosmological solutions of Einstein's equations. They provide new information about the nature of general cosmological solutions to Einstein's equations.

General Relativity and Quantum Cosmology · Physics 2007-05-23 John D. Barrow , Kerstin E. Kunze
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