Possible existence of ghost stars in the context of electromagnetic field

Abstract

In this paper, we discuss the existence of ghost star models in the Einstein–Maxwell framework. In order to explore these objects, we put forward the idea of Zeldovich and Novikov by keeping in mind that the energy density of such models lie in the negative range in some regions of the spacetime geometry. We proceed by taking into account a static sphere and develop the field equations for a charged anisotropic fluid configuration. The two generating functions are then considered and we rewrite the field equations in terms of the mass and these physical quantities. Afterwards, we formulate two different models using the conformally flatness condition along with the considered generating functions. Further, we adopt the vanishing complexity constraint as well as null active gravitational mass to find two more solutions. The energy density for all developed models is also graphically shown. We conclude that the ghost stars exist in the presence of charge as the energy density for all the resulting solutions lie in the negative region for a particular range of the radial coordinate.