Related papers: Aligning spinning black holes and accretion discs
I show in this paper that two types of magnetic torques can appear in the interaction between an accretion disc and a magnetic accretor. There is the well-known torque resulting from the difference in angular velocity between the accretion…
We discuss the problem of the formation of a large-scale magnetic field in the accretion disks around black holes, taking into account the non-uniform vertical structure of the disk. The high electrical conductivity of the outer layers of…
We analyze the temporal evolution of accretion onto rotating black holes subject to large-scale magnetic torques. Wind torques alone drive a disk towards collapse in a finite time $\sim t_{ff} E_k/E_B$, where $t_{ff}$ is the initial…
Angular tension is an ADM charge that contributes a work term to the first law of black hole mechanics when the range of an angular coordinate is varied and leads to a new Smarr formula for stationary black holes. A phase diagram for…
The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Further, spin can be a potent energy source for powering relativistic jets and energetic particle…
We investigate the axially symmetric accretion of low angular momentum hydrodynamic matter onto a rotating black hole. The gravitational field under consideration is assumed to be described by a pseudo-Newtonian Kerr potential. The…
We study the basic properties of accretion flows onto binary supermassive black holes, including the cases in which a circumbinary disk is misaligned with the binary orbital plane, by means of three-dimensional Smoothed Particle…
Spin precession occurs in binary black holes whose spins are misaligned with the orbital angular momentum. Otherwise, the spin configuration is constant and the subsequent binary dynamics and gravitational-wave emission are much simpler. We…
We consider the evolution of a warped disc around a Kerr black hole, under conditions such that the warp propagates in a wavelike manner. This occurs when the dimensionless effective viscosity, alpha, that damps the warp is less than the…
An inspiralling object of mass $\mu$ around a Kerr black hole of mass $M (\gg \mu)$ experiences a continuous transition near the innermost stable circular orbit from adiabatic inspiral to plunge into the horizon as gravitational radiation…
We develop a relativistically accurate formalism to model the interaction between stellar mass compact objects embedded in thin accretion disks around a non-spinning supermassive black hole, using tools from self-force theory and…
We construct smooth supergravity solutions describing a BPS black ring with a BPS black hole centered at an arbitrary distance above the ring. We find that as one moves the black hole the entropy of the ring remains constant, but the…
In this paper, we report on the first 3D general relativistic radiation magnetohydrodynamic simulations of large supercritical accretion discs that are tilted with respect to the black hole spin axis. We explore a range of black hole spin…
The peaks of the spectra of the accretion disks surrounding massive black holes in quasars are in the far-UV or soft X-ray band, which are usually not observed. However, in the disk corona model, the soft photons from the disk are…
We provide a description of a thin accretion disc for a static spherically symmetric black holes in $f(R)$ gravity. In this regard, we first study the horizons of black holes in $f(R)$ gravity. The equation of motion and effective potential…
The spin of the final black hole in the coalescence of nonspinning black holes is determined by the ``residual'' orbital angular momentum of the binary. This residual momentum consists of the orbital angular momentum that the binary is not…
Massive black holes in galactic nuclei vary their mass M and spin vector J due to accretion. In this study we relax, for the first time, the assumption that accretion can be either chaotic, i.e. when the accretion episodes are randomly and…
In this paper, we present the stationary axisymmetric configuration of a resistive magnetised thick accretion disc in the vicinity of external gravity and intrinsic dipolar magnetic field of a slowly rotating black hole. The plasma is…
Combined influence of rotation of a black hole and ambient magnetic fields creates conditions for powerful astrophysical processes of accretion and outflow of matter which are observed in many systems across the range of masses; from…
Nowadays we believe that a typical galaxy contains about $10^7$ stellar-mass black holes and a single super-massive black hole at its center. According to general relativity, these objects are characterized solely by their mass $M$ and by…