Related papers: Simple Black Holes with Anisotropic Fluid
We consider static neutron stars within the framework of $R^2$ gravity. The neutron fluid is described by three different types of realistic equations of state (soft, moderately stiff, and stiff). Using the observational data on the neutron…
Adopting noncommutative spacetime coordinates, we determined a new solution of Einstein equations for a static, spherically symmetric matter source. The limitations of the conventional Schwarzschild solution, due to curvature singularities,…
Recently introduced exact solution of the Einstein gravity coupled minimally to an anisotropic fluid representing dark matter can well represent supermassive black holes in galactic nuclei with realistic distribution of dark matter around…
Motivated by possible relation between Born-Infeld type nonlinear electrodynamics and an effective low-energy action of open string theory, asymptotically Reissner--Nordstrom black holes whose electric field is described by a nonlinear…
A class of nonstationary spacetimes is obtained by means of a conformal transformation of the Schwarzschild metric, where the conformal factor $a(t)$ is an arbitrary function of the time coordinate only. We investigate several situations…
We obtain relativistic solutions of spherically symmetric accretion by a dynamical analysis of a generalised Hamiltonian for higher-dimensional Reissner-Nordstr\"{o}m (RN) Black Hole (BH). We consider two different fluids namely, an…
Unique features of particle orbits produce novel signatures of gravitational observable phenomena, and are quite useful in testing compact astrophysical objects in general relativity or modified theories of gravity. Here we observe a…
We study the physical process of gravitational collapse of a perfect fluid with a linear isentropic equation of state $p = k \rho, \ -1/3 < k \leq 1$. We consider a model with ansatz $v'(t,r)/v(t,r) = \xi'(r)$ that give rise to a family of…
Regular black hole solutions are found among the Guilfoyle exact solutions. These are spherically symmetric solutions of general relativity coupled to Maxwell's electromagnetism and charged matter where the metric potentials and…
Using a recently developed generalized Weyl formalism, we construct an asymptotically flat, static vacuum Einstein solution that describes a superposition of multiple five-dimensional Schwarzschild black holes. The spacetime exhibits a…
We present a time dependent isotropic fluid solution around a Schwarzschild black hole. We offer the solutions and discuss the effects on the field equations and the horizon. We derive the energy density, pressure and the equation of state…
We present numerical evidences for the validity of the inequality between the total mass and the total angular momentum for multiple axially symmetric (non-stationary) black holes. We use a parabolic heat flow to solve numerically the…
We investigate the physical and observational features of static, spherically symmetric black hole spacetimes surrounded by anisotropic fluid and embedded in a plasma environment. Motivated by recent advances in black hole imaging and…
Shape dynamics is a classical theory of gravity which agrees with general relativity in many important aspects, but which possesses different gauge symmetries and can present some fundamental global differences with respect to Einstein…
A new class of analytic charged spherically symmetric black hole solutions, which behave asymptotically as flat or (A)dS spacetimes, is derived for specific classes of $f(R)$ gravity, i.e., $f(R)=R-2\alpha\sqrt{R}$ and…
Using a novel numerical spectral method, we have found solutions for large static Randall-Sundrum II (RSII) black holes by perturbing a numerical AdS_5-CFT_4 solution to the Einstein equation with a negative cosmological constant Lambda…
A new class of solutions describing analytical solutions for compact stellar structures has been developed within the tenets of General Relativity. Considering the inherent anisotropy in compact stars, a stable and causal model for…
The general metric for N-dimensional spherically symmetric and conformally flat spacetimes is given, and all the homogeneous and isotropic solutions for a perfect fluid with the equation of state $p = \alpha \rho$ are found. These solutions…
It is formulated a new 'anholonomic frame' method of constructing exact solutions of Einstein equations with off--diagonal metrics in 4D and 5D gravity. The previous approaches and results are summarized and generalized as three theorems…
We present a simple spherically symmetric and regular solution of Einstein's equations with two parameters $k$ and $M$, which matches to Schwarzschild's solution, satisfies the weak energy conditions in the interior region and for small $r$…