Solutions Of Einstein-Maxwell Equations Research Articles

Equatorial Geodesics Around the Magnetars

Neutron stars manifest themselves as different classes of astrophysical sources that are associated to distinct phenomenology. Here we focus our attention on magnetars (or strongly magnetized neutron stars) that are associated to Soft Gamma Repeaters and Anomalous X-ray Pulsars. The magnetic field on surface of these objects, reaches values greater than [Formula: see text] G. Under intense magnetic fields, relativistic effects begin to be decisive for the definition of the structure and evolution of these objects. We are tempted to question ourselves to how strengths fields affect the structure of neutron star. In this work, our objective is study and compare two solutions of Einstein-Maxwell equations: the Bonnor solution, which is an analytical solution that describe the exterior spacetime for a massive compact object which has a magnetic field that is characterize as a dipole field and a complete solution that describe the interior and exterior spacetime for the same source found by numerical methods). For this, we describe the geodesic equations generated by such solutions. Our results show that the orbits generated by the Bonnor solution are the same as described by numerical solution. Also, show that the inclusion of magnetic fields with values up to [Formula: see text]G in the center of the star does not modify sharply the particle orbits described around this star, so the use of Schwarzschild solution for the description of these orbits is a reasonable approximation.

-Type Plane Wave Solution of E-M Equations Coexisting with Null Fluid and Null Current in Space-Time V 5

In this paper, we have shown that generalized plane wave metric be the solution of Einstein-Maxwell equations in the presence of null fluid and null currents in higher dimensional space-time V 5 for -type plane wave and also discussed some particular cases.

Static charged fluid around a massive magnetic dipole

An analytical solution of Einstein-Maxwell equations with a static fluid as a source is presented. The spacetime is represented by the axially symmetric Weyl metric and the energy-momentum tensor describes a coupling of a fluid with an electromagnetic field. When appropriate limits are performed we recover the well-known solutions of Gutsunaev-Manko and Schwarzschild. Also, using Eckart's thermodynamics, we calculated the temperature, the mechanical pressure, the charge density, and the energy density of the system. The analysis of thermodynamic quantities suggests that the solution can be used to represent a magnetized compact stellar object surrounded by a charged fluid.

Classical model of an elementary particle with a Bertotti-Robinson core and extremal black holes

We discuss the question, whether the Reissner-Nordstr\"om (RN) metric can be glued to other solutions of Einstein-Maxwell equations in such a way that (i) the singularity at $r=0$ typical of the RN metric is removed, and (ii) matching is smooth. Such a construction could be viewed as a classical model of an elementary particle balanced by its own forces without support by an external agent. One choice is the Minkowski interior that goes back to the old Vilenkin and Fomin's idea who claimed that in this case the bare deltalike stresses at the horizon vanish if the RN metric is extremal. However, the relevant entity here is the integral of these stresses over the proper distance which is infinite in the extremal case. As a result of the competition of these two factors, the Lanczos tensor does not vanish and the extremal RN cannot be glued to the Minkowski metric smoothly, so the elementary-particle model as an empty ball inside fails. We examine the alternative possibility for the extremal RN metric---gluing to the Bertotti-Robinson (BR) metric. For a surface placed outside the horizon there always exist bare stresses but their amplitude goes to zero as the radius of the shell approaches that of the horizon. This limit realizes the Wheeler idea of ''mass without mass'' and ''charge without charge.'' We generalize the model to the extremal Kerr-Newman metric glued to the rotating analog of the BR metric.

A New Solution of Einstein-Maxwell Equations

A new generation theorem for Einstein-Maxwell field is attained. According to it, a new solution of Einstein-Maxwell equations can be generated from a static vacuum solution. Starting with Schwarzschild solution, a new solution of the Einstein-Maxwell equations is obtained by means of this theorem.

Some new radiating Kerr-Newman solutions

Three exact non-static solutions of Einstein-Maxwell equations corresponding to a field of flowing null radiation plus an electromagnetic field are presented. These solutions are non-static generalizations of the well known Kerr-Newman solution. The current vector is null in all the three solutions. These solutions are the electromagnetic generalizations of the three generalized radiating Kerr solutions discussed by Vaidya and Patel. The solutions discussed by us describe the exterior gravitational fields of rotating radiating charged bodies. Many known solutions are derived as particular cases.

Conformally symmetric anisotropic magnetospheres in general relativity

A class of exact analytical solutions of Einstein-Maxwell equations is obtained for static spheres of Maugin's anisotropic magnetofluid where the space-time geometry is assumed to admit a nonstatic conformai symmetry. These solutions are found by utilizing special physical considerations.

Axially-symmetric quasi-neutral charged dust distributions in general relativity

A solution of Einstein-Maxwell equations representing a distribution of equal and opposite charges moving in circles in opposite directions around thez-axis is obtained. In a particular case the solution reduces to the special case of Levi-Civita metric for a line-mass placed along thez-axis. The asymptotic behaviour of the solution is also discussed.

Anisotropic Bianchi types VIII and IX locally rotationally symmetric cosmologies

We present a class of exact cosmological solutions of Einstein-Maxwell equations, which are anisotropic and spatially homogeneous of Bianchi types VIII and IX, and class IIIb in the Stewart-Ellis classification of locally rotationally symmetric models. If we take the electromagnetic field equal to zero, a class of Bianchi types VIII/IX spatially homogeneous anisotropic cosmological solutions with perfect fluid is obtained.

Invariance of the electromagnetic field in static space-times

Using the Debever formalism and classical geometrodynamics it is shown that in a static space-time, solution of Einstein-Maxwell equations, the electromagnetic field is also static.

Some type-G solution of electrovac equations

A charged solution of Einstein-Maxwell equations which contains five real parameters is presented. This solution is of typeG and, in the limiting transition, it reduces to the subbranch ofD-solutions characterized by the vanishing of the complex expansion.

Some new exact solutions of Einstein-Maxwell equations with axial symmetry

Some new exact solutions of Einstein-Maxwell equations with axial symmetry

A class of axisymmetric stationary exact solutions of Einstein-Maxwell equations

Einstein-Maxwell vacuum field equations of an axially symmetric stationary charged rotating source are studied. A class of asymptotically flat solutions representing the exterior field of a stationary rotating charged oblate spheroidal source is obtained. By examining eigenvectors of Einstein tensor Gij, invariants RijRij and Petrov classification of Weyl's conformal tensor, it is proved that the metric potentials describe null electromagnetic fields.

Five-Parameter Exterior Solution of the Einstein-Maxwell Field Equations

A five-parameter solution of the combined Einstein-Maxwell equations is given which describes a source containing mass, electric charge, magnetic dipole, higher multipole moments of all three kinds, and angular momentum. The solution is obtained by using Kinnersley's method of generating stationary Einstein-Maxwell fields from known solutions of the Einstein-Maxwell equations. We start with a two-parameter solution of a system having mass and a magnetic dipole moment discovered by Misra, Pandey, Srivastava, and Tripathi. All solutions discussed in this paper are asymptotically flat, and all have infinite red-shift surfaces that are singular. Possible relevance of these solutions to black-hole physics is remarked upon.

Null electromagnetic fields in a general relativity

The author presents a class of solutions of Einstein-Maxwell equations corresponding to stationary null electromagnetic fields in otherwise empty space.