Related papers: The evolution of black-hole mass and angular momen…
We analyze the dynamical evolution of binary stars that interact with a static background of single stars in the environment of a massive black hole (MBH). All stars are considered to be single mass, Newtonian point particles. We follow the…
We address the role of large scale magnetic stress in the angular momentum transport, as well as the formation of different kinds of magnetic barrier in geometrically thick, optically thin, vertically averaged 1.5-dimensional advective…
We present three-dimensional Smoothed Particle Hydrodynamics (SPH) simulations investigating the dependence of the accretion rate on the disc thickness around an equal-mass, circular black hole binary system. We find that for thick/hot…
We study the coupled disc-jet system around the black hole where the outflow solutions are obtained in terms of the inflow parameters. We observe that an advective accretion disc can eject outflows/jets for wide range of viscosity…
In certain scenarios, the accreted angular momentum of plasma onto a black hole could be low; however, how the accretion dynamics depend on the angular momentum content of the plasma is still not fully understood. We present…
From the postulate that a black hole can be replaced by a boundary on the apparent horizon with suitable boundary conditions, an unconventional scenario for the evolution emerges. Only an insignificant fraction of energy of order…
The mass of a black hole is the sum of the irreducible mass and the mass associated with the rotational or spin energy of the black hole. The contribution of spin energy (divided by $c^2$) to the total black hole mass is studied here for…
In this paper, we consider angular momentum fluctuations of a Schwartzschild black hole in thermal equilibrium with radiation which, for the sake of simplicity is here modeled by a scalar field. Important, we do not set the black hole…
The highest efficiency of converting rest mass into energy by accreting matter into a Kerr black hole is ~ 31% (Thorne 1974). We propose a new process in which periods of accretion from a thin disk, and the associated spin-up of the black…
We use numerical simulations of scalar field dark matter evolving on a moving black hole background to confirm the regime of validity of (semi-)analytic expressions derived from first principles for both dynamical friction and momentum…
Rotating black holes are known to launch relativistic jets and accelerate particles provided they accrete a magnetized plasma. However, it remains unclear how the global magnetic field orientation affects the jet powering efficiency. Here,…
We consider transient behavior in low-mass X-ray binaries. In short-period neutron-star systems (orbital period less than ~ 1d) irradiation of the accretion disk by the central source suppresses this except at very low mass transfer rates.…
We consider rotating Primordial black holes (PBHs) and study the effect of accretion of radiation in the radiation dominated era. The central part of our analysis deals with the role of the angular momentum parameter on the evolution of…
Black hole binaries exhibit dramatic changes in their X-ray spectral and timing properties over time, providing important clues about the physical processes that occur in these systems. Black holes and black hole candidates are prime…
Discerning the likelihood of the so-called runaway instability of thick accretion disks orbiting black holes is an important issue for most models of cosmic gamma-ray bursts. To this aim we investigate this phenomenon by means of…
We consider the interaction between a plane wave and a (counter-moving) black hole. We show that energy is transferred from the black hole to the wave, giving rise to a negative absorption cross-section. Moving black holes absorb radiation…
We study properties of particles with zero or negative energy and a nonzero orbital angular momentum in the ergosphere of a rotating black hole. We show that the sign of the particle energy is uniquely determined by the angular velocity of…
We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results…
A spinning black hole accreting from a disk of strongly magnetized plasma via a magnetically arrested disk is known to produce an efficient electromagnetic jet powered by the black hole's spin energy. We present general relativistic…
We model a circular mass-transferring binary system to calculate the exchange of angular momentum between stellar spins and the orbit due to direct impact of the mass transfer stream onto the surface of the accretor. We simulate mass…