Perfect Fluid Distribution Research Articles

Bianchi Type-I Massive String Magnetized Barotropic PerfectFluid Cosmological Model in General Relativity

Bianchi type-I massive string cosmological model with magnetic field ofbarotropic perfect fluid distribution through the techniques used byLatelier and Stachel is investigated. To obtain the deterministic modelof the universe, it is assumed that the universe is filled withbarotropic perfect fluid distribution. The magnetic field is due toelectric current produced along the x-axis with infinite electricalconductivity. The behaviour of the model in the presence and absence ofmagnetic field together with other physical aspects is furtherdiscussed.

Five dimensional cosmological models in Lyra geometry with time dependent displacement field

In this paper exact solutions of the five-dimensional vacuum cosmological field equations based on Lyra geometry are obtained. Further it is shown that neither dust distribution nor perfect fluid distributions survive for the model. Some properties of the vacuum model are also discussed.

Some cosmological models with heat and null radiation flow

Some New Bianchi type-V cosmological models, incorporating heat flow and null radiation flow, along with perfect fluid distribution have been discussed. The physical and kinematical behaviors of the models have been analyzed.

Non-Existence of Five Dimensional Perfect Fluid Cosmological Model in Lyra Manifold

In this paper we have taken an attempt to construct a five dimensional perfect fluid cosmological model within the framework of Lyra manifold. It is found that neither perfect fluid nor dust distributions survive. Finally the exact solutions of the vacuum field equations are obtained.

Static charged distributions in2+1gravity

Circularly symmetric charged perfect-fluid distributions are studied in three-dimensional gravity with a cosmological constant. We derive the Tolman-Oppenheimer-Volkoff equation of hydroelectrostatic equilibrium, and we discuss its applicability. A class of charged fluid distributions for $p=\ensuremath{-}\ensuremath{\rho}$ is considered. In this case, a particular model is obtained which represents a charged distribution whose mass is entirely of electromagnetic origin.

Einstein–Rosen Universe in a Scalar-Tensor Theory of Gravitation

Field equations in the presence of a perfect fluid distribution are obtained in a scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.113, 1985, 467) with the aid of Einstein–Rosen cylindrically symmetric metric. A static vacuum model and a non-static stiff fluid model are presented. The physical and geometrical properties of the stiff fluid model are studied.

Charged sphere of shear-free fluids with $$\frac{\partial}{\rho} \partial r \leq 0$$

The Einstein-Maxwell equations for non-static charged shear-free spherically symmetric perfect fluid distribution reduce to a second-order non-linear differential equation in the radial parameter. Several solutions of this equation have been obtained in earlier work without considering the general requirement for physical relevance of the solutions. Generally physically acceptable relativistic fluid models demand that the solutions satisfy the reality conditions ρ ≥ 0, p ≥ 0, ρr ≤ 0, etc. throughout the fluid model. In this article the expression for density gradient ρ x (or ρr) has been utilized to produce charged shear-free relativistic fluid models with non-positive density gradient (NDG)ρr ≤ 0. Eventually, we have found that none of the Riccati solutions have NDG including Vaidya metric. Also, the solutions with NDG neither possess Lie-symmetries nor Painleve property. Further, it is observed that the solutions with NDG have no uncharged analogue.

Non-Static Plane Symmetric Zeldovich Fluid Model In ScaleInvariant Theory

We study the perfect fluid distribution in scale invariant theory ofgravitation, when the spacetime is described by non-static planesymmetric metric with a time-dependent gauge function. The Zeldovichmodel of the universe is constructed and some physical properties ofthe model are discussed.

Non-static plane symmetric cosmological model in Wesson’s theory

The problem of non-static plane symmetric perfect fluid distribution in Wesson’s [1] scale invariant theory of gravitation with a time-dependent gauge function is investigated. The false vacuum model of the universe is constructed and some physical properties of the model are discussed.

Letter: Static Plane Symmetric Cosmological Model in Wesson's Theory

The problem of static plane symmetric perfect fluid distribution in Wesson's scale invariant theory of gravitation with a time dependent gauge function is investigated. The cosmological model of the universe is constructed and some physical properties of the model are discussed.

Tilted bianchi type I stiff fluid magnetized cosmological model in general relativity

Tilted Bianchi Type I cosmological model for perfect fluid distribution in presence of magnetic field, is investigated. To get a determinate solution, it has been assumed that the universe is filled with stiff perfect fluid distribution together with A=(BC)n where A,B,C are metric potentials and n is a constant. The behaviour of the model in presence and absence of magnetic field is discussed. The various physical and geometrical aspects of the model, is also discussed. It has been shown that tilted nature of the Bianchi Type I model is preserved due to magnetic field.

Bianchi Type-1 vacuum models in modified theory of general relativity

In this paper, the problem of spatially homogeneous and an isotropic Bianchi type-1 space time with perfect fluid distribution is considered in Barber's second theory of gravitation. To obtain determinate solutions, we have assumed the equation of statep= γρ, 0 ≤ γ ≤ 1. It is observed that the general fluid distribution degenerates isotropic vacuum model whenγ = 1 and Λ < 0. Further it is observed that the vacuum model obtained in case of γ = 0, ρ = 0 andΛ = 0, reduces to well known Kasner model in Einstein's theory. Some physical and geometrical aspects of the models together with singularities in the models are also discussed

Bianchi VI0cosmological model in Saez and Ballester theory

The problem of perfect fluid distribution in spatially homogeneous and anisotropic Bianchi type VI0 space-time is considered in a scalar tensor theory of gravitation proposed by Saez and Ballester (1985). Exact solutions of the field equations are derived when the metric potentials are functions of cosmic time only. Some physical and geometrical properties of the solutions are also discussed.

Bianchi Type V False Vacuum Cosmological Model in Scale-Invariant Theory

Intention of this paper is to study the perfect fluid distribution in scale-invariant theory of gravity when the space-time is described by Bianchi type V metric with a time-dependent gauge function (Dirac gauge). In this theory the false vacuum model of the universe is constructed and physical behaviors of the model is discussed.

Bianchi type I cosmological perfect fluid model in scale invariant theory

The intention of this paper is to study the perfect fluid distribution in scale invariant theory of gravity when the space-time is described by Bianchi type I metric with a time dependent gauge function. The cosmological equations for this space-time with gauge function are solved and some physical properties of the model are discussed.

Vacuum Cosmological Models in Einstein and Barber Theories

An attempt has been made to solve the field equations with perfect fluid in an inhomogeneous space-time governed by the metric $$ds^2 = dt^2 - dx^2 - y^2 - dz^2 + f\left( {t - x,y,z} \right)\left( {dt - dx} \right)^2$$ in both Einstein and Barber's theories of gravitation. It is shown here that in both the theories the field equations are reducible to a Laplace equation and the perfect fluid distribution does not survive. Moreover all the solutions represent plane gravitational wave and the vacuum models in both the theories can be constructed by an arbitrary harmonic function iny and z coordinates.

Bianchi Type VI1 Cosmological Model in Scale-Invariant Theory

In this paper, an attempt has been taken to study the perfect fluid distribution in the scale invariant theory of gravitation, when the space-time described by Bianchi type V metric with a time dependent gauge function. In this theory, a non-singular steady state model of the universe is constructed and some physical behaviors of the model are studied.

Some Inhomogeneous Perfect Fluid Cosmological Models in the Presence of Electromagnetic Field

Some cylindrically symmetric inhomogeneous cosmological models for perfect fluid distributions with electromagnetic field are obtained. To get a determinate solution, a supplementary condition between metric potentials is used. Various physical and geometrical properties of the models with some special cases are also discussed.

Static Spherically Symmetric Perfect Fluid Distribution in Presence of Electromagnetic Field

In this paper a solution corresponding to a static spherically sym- metric perfect uid distribution in presence of electromagnetic field which is a natural generalization of the well-known Reissner–Nordstrom solution is discussed with a two-parameter family of line-elements. The space-time is asymptotically at. The integrating constants are determined by matching the obtained solution with the Reissner–Nordstrom solution over the boundary. It has been found that the uid model has non-negative expression for the mass density and pressure.

Bianchi Type I Anisotropic Magnetized Cosmological Model in General Relativity

Bianchi Type I magnetized Cosmological model for perfect fluid distribution is investigated. The magnetic field is due to an electric current produced along x-axis. The distribution consists of an electrically neutral perfect fluid with an infinite electrical conductivity. To get a determinate solution, a supplementary conditionA = BC between metric potentials is used. The behaviour of the model in presence and absence of magnetic field is also discussed.