Compelling alternatives to black holes, namely, gravitational vacuum stars （gravastars）, which are multilayered compact objects, have been proposed to avoid a number of theoretical problems associated with event hor...Compelling alternatives to black holes, namely, gravitational vacuum stars （gravastars）, which are multilayered compact objects, have been proposed to avoid a number of theoretical problems associated with event horizons and singularities. In this work, we construct a spherically symmetric thin-shell charged gravastar model where the vacuum phase transition between the de Sitter interior and the external Reissner-Nordstrom spacetime （RN） are matched at a junction surface, by using the cut-and-paste procedure. Gravastar solutions are found among the Guilfoyle exact solutions where the gravitational potential We and the electric potential field Ф obey a particular relation in a simple form a（b-εФ）^2＋b1, where a, b and bl are arbitrary constants. The simplest ansatz of Guilfoyle＇s solution is implemented by the following assumption： that the total energy density 8πρm＋Q^2/r^4 is constant, where Q（r） is the electric charge up to a certain radius r. We show that, for certain ranges of the parameters, we can avoid the horizon formation, which allows us to study the linearized spherically symmetric radial perturbations around static equilibrium solutions. To lend our solution theoretical support, we also analyze the physical and geometrical properties of gravastar configurations.展开更多
文摘Compelling alternatives to black holes, namely, gravitational vacuum stars （gravastars）, which are multilayered compact objects, have been proposed to avoid a number of theoretical problems associated with event horizons and singularities. In this work, we construct a spherically symmetric thin-shell charged gravastar model where the vacuum phase transition between the de Sitter interior and the external Reissner-Nordstrom spacetime （RN） are matched at a junction surface, by using the cut-and-paste procedure. Gravastar solutions are found among the Guilfoyle exact solutions where the gravitational potential We and the electric potential field Ф obey a particular relation in a simple form a（b-εФ）^2＋b1, where a, b and bl are arbitrary constants. The simplest ansatz of Guilfoyle＇s solution is implemented by the following assumption： that the total energy density 8πρm＋Q^2/r^4 is constant, where Q（r） is the electric charge up to a certain radius r. We show that, for certain ranges of the parameters, we can avoid the horizon formation, which allows us to study the linearized spherically symmetric radial perturbations around static equilibrium solutions. To lend our solution theoretical support, we also analyze the physical and geometrical properties of gravastar configurations.
