Related papers: Effects of Fluid Composition on Spherical Flows ar…
Matter falling onto black holes is hot, fully ionized and has to be necessarily transonic. Since the electrons are responsible for radiative cooling via processes like synchrotron, bremsstrahlung and inverse-Compton, therefore the electron…
A spacetime endowed with an anisotropic fluid is proposed for the interior of a Schwarzschild black hole. The geometry has an instantaneous Minkowski form and is a solution of Einstein's equations with a stress tensor on the r.h.s. obeying…
Results are presented from a time--dependent, numerical investigation of spherical accretion onto black holes, within the framework of relativistic radiation hydrodynamics. We have studied the stability of self--consistent, stationary…
We study a slightly rotating accretion flow onto a black hole, using the fully three dimensional (3-D)numerical simulations. We consider hydrodynamics of an inviscid flow, assuming a spherically symmetric density distribution at the outer…
Analytical studies and numerical simulations of time dependent axially symmetric flows onto black holes have shown that it is possible to produce stationary shock waves with a stable position both for ideal inviscid and for moderately…
The effect of cooling on the outflow rate from an accretion disk around a black hole is investigated using a coupled Monte Carlo Total Variation Diminishing code. A correlation between the spectral states and the outflow rates is found as a…
We present a simple, analytic and straightforward method to elucidate the effects produced by polytropic fluids on any other gravitational source, no matter its nature, for static and spherically symmetric spacetimes. As a direct…
In this work, starting from a spherically symmetric polytropic black hole, a rotating solution is obtained by following the Newman--Janis algorithm without complexification. Besides studying the horizon, the static conditions and causality…
In this paper we analyze the large-time behavior of weak solutions to polytropic fluid models possibly including quantum and capillary effects. Formal a priori estimates show that the density of solutions to these systems should disperse…
In high energy heavy ion collisions and interacting cold atom systems, large elliptic flow anisotropies have been observed. For the large opacity ($\rho\sigma L\sim 10^{3}$) of the latter hydrodynamics is a natural consequence, but for the…
The four-dimensional Friedman flat universe, filled with an ideal fluid with a linear (oscillating) inhomogeneous equation of state (EoS) depending on time, is studied. The equations of motion are solved. It is shown that in some cases…
Looking for the underlying hydrodynamic mechanisms determining the elliptic flow we show that for an expanding relativistic perfect fluid the transverse flow may derive from a solvable hydrodynamic potential, if the entropy is transversally…
It has been shown that the nonthermal spectrum of Hawking radiation will lead to information-carrying correlations between emitted particles in the radiation. The mutual information carried by such correlations can not be locally observed…
The field equations of static, spherically symmetric geometries generated by anisotropic fluids is investigated with the aim of better understanding the relation between the matter and the emergence of minimal area throats, like in wormhole…
We investigate the accretion process for different spherically symmetric space-time geometries for a static fluid. We analyse this procedure using the most general black hole metric ansatz. After that, we examine the accretion process for…
We review the issue of steady spherically symmetric accretion onto a renormalization group improved Schwarzschild space-time which is solution to an asymptotically safe theory (AS) containing high-derivative terms. We use a Hamiltonian…
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 investigate spherical, isothermal and polytropic steady accretion models in the presence of the cosmological constant. Exact solutions are found for three classes of isothermal fluids, assuming the test gas approximation. The…
We investigate the motion of a massive particle around a spherically symmetric black hole surrounded by a stationary and radial inflow of perfect fluid. The background spacetime is modelled as a spherically symmetric solution to the…
We studied the process of decoherence induced by the presence of an environment in acoustic black holes, using the open quantum system approach, thus extending previous work. We focused on the ion trap model but the formalism is general to…