Dubravko Horvat, Saša Ilijic, Anja Marunovic (Zagreb):
Charged Gravastar
Abstract:
The notion of a compact object immune of the horizon
problem and comprising of an anisotropic inhomogenous fluid with specific radial pressure behavior,
i.e. the gravastar, is extended by introducing an electric charged component. Einstein field
equations are solved together with EinsteinMaxwell equation, where source of the electric field
is tied to the fluid energy density. The coupled nonlinear problem is solved at different levels
of complexity and sophistication with the aim to show that solutions which bear all the features
of the gravastar could be find in situations where conditions for their existence are being pushed
to their limit. In the analisys of the obtained results it is shown that the charged component of
the total gravastar configuration has to be mixed with caution since the sensitive condition for
the absence of the horizon could be violated. Also, the charged configuration is shown to belong
to large class of solutions which in certain limit could reach the stage of quasi black holes.
