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We study a spherically symmetric spacetime made of anisotropic fluid of which radial equation of state is given by $p_1 = -rho$. This provides analytic solutions and a good opportunity to study the static configuration of black hole plus matter. For a given equation-of-state parameter $w_2 = p_2/rho$ for angular directions, we find exact solutions of the Einsteins equation described by two parameters. We classify the solution into six types based on the behavior of the metric function. Depending on the parameters, the solution can have event and cosmological horizons. Out of these, one type corresponds to a generalization of the Reissiner-Nordstrom black hole, for which the thermodynamic properties are obtained in simple forms. The solutions are stable under radial perturbations.
We investigate the gravitational field of static perfect-fluid in the presence of electric field. We adopt the equation of state $p(r)=-rho(r)/3$ for the fluid in order to consider the closed ($S_3$) or the open ($H_3$) background spatial topology. D
We investigate black holes formed by static perfect fluid with $p=-rho/3$. These represent the black holes in $S_3$ and $H_3$ spatial geometries. There are three classes of black-hole solutions, two $S_3$ types and one $H_3$ type. The interesting sol
We study spherically symmetric geometries made of anisotropic perfect fluid based on general relativity. The purpose of the work is to find and classify black hole solutions in closed spacetime. In a general setting, we find that a static and closed
We present a family of new rotating black hole solutions to Einsteins equations that generalizes the Kerr-Newman spacetime to include an anisotropic matter. The geometry is obtained by employing the Newman-Janis algorithm. In addition to the mass, th
Recently neutral and charged black-hole solutions were found for static perfect fluid with the equation of state $p(r)=-rho(r)/3$, for fluid only as well as for fluid in the presence of electric field. In those works, the stability of the black holes