相关论文: Relativistic Diskoseismology
The inner part of a thin accretion disk around a Kerr black hole can serve as an important tool to study the physics of the strong gravity regime. A tilt in such a disk with respect to the black hole spin axis is particularly useful for…
We analyze stationary self-gravitating disks around spinning black holes that satisfy the recently found general-relativistic Keplerian rotation law. There is a numerical evidence that the angular velocity, circumferential radius and…
We investigate the accretion induced spin up of the black hole via numerical simulations. Our method is based on general-relativistic magneto-hydrodynamics of the slowly-rotating flows in the Kerr metric, where possibly transonic shock…
Accretion disks are observed in young stars, cataclysmic variables, binary X-ray sources et al. Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was…
The geometry of black hole spacetimes can be probed with exquisite precision in the gravitational-wave window, and possibly also in the optical regime. We study the accretion of bright spots -- objects which emit strongly in the optical or…
Coalescing binary black holes emit anisotropic gravitational radiation. This causes a net emission of linear momentum that produces a gradual acceleration of the source. As a result, the final remnant black hole acquires a characteristic…
Observations of accreting systems often show significant variability (10-20 percent of accretion luminosity) on timescales much longer than expected for the disc regions releasing most of the luminosity. We propose an explicit physical…
The low-energy dynamics of any system admitting a continuum of static configurations is approximated by slow motion in moduli (configuration) space. Here, following Ferrell and Eardley, this moduli space approximation is utilized to study…
A model for determining the dimensionless spin parameter and mass of the black hole remnant of black hole-neutron star mergers with arbitrary initial black hole spin angular momentum, binary mass ratio, and neutron star mass and cold…
Relativistic reflection features are commonly observed in the X-ray spectra of accreting black holes. In the presence of high quality data and with the correct astrophysical model, X-ray reflection spectroscopy can be quite a powerful tool…
(Abridged) We study the dynamical evolution of a stationary, axisymmetric, and perfectly conducting cold accretion disk containing a large-scale magnetic field around a Kerr black hole, trying to understand the relation between accretion…
We study the hydrodynamical evolution of massive accretion disks around black holes, formed when a neutron star is disrupted by a black hole in a binary system. Initial conditions are taken from 3D calculations of coalescing binaries.…
We discuss the structure of a central stellar cluster whose dynamics is influenced by gravitation of a supermassive black hole and by the dissipative interaction of orbiting stars with an accretion disc. We also take the effect of disc…
We prescribe a method to study the effects of self-gravity of accretion disk around a black hole associated with long Gamma Ray Bursts (GRBs) in an evolving background Kerr metric. This is an extension to our previous work where we…
In this review article I attempt to summarise past and present-ongoing-work on the problem of the inspiral of a small body in the gravitational field of a much more massive Kerr black hole. Such extreme mass ratio systems, expected to occur…
We show that disc continuum fitting can be used to constrain black hole spin in a subclass of Narrow Line Seyfert 1 (NLS1) AGN as their low mass and high mass accretion rate means that the disc peaks at energies just below the soft X-ray…
The Rossi X-Ray Timing Explorer (RXTE) has found that the neutron stars in low-mass X-ray binaries exhibit oscillations in the range 300-1200 Hz. Persistent emission may exhibit one or both of two features. In bursts a nearly coherent…
These notes introduce and review some of the physical principles underlying the theory of astrophysical accretion, emphasizing the central roles of angular momentum transport, angular momentum loss, and radiative cooling in determining the…
Analyzing test particles falling into a Kerr black hole, we study gravitational waves in Brans-Dicke theory of gravity. First we consider a test particle plunging with a constant azimuthal angle into a rotating black hole and calculate the…
Tidal disruptions of stars on the equatorial plane orbiting Kerr black holes have been widely studied. However thus far, there have been fewer studies of stars in inclined precessing orbits around a Kerr black hole. In this paper, we use…