Related papers: Expectations for extreme-mass-ratio bursts from th…
The coherent torques between stars on orbits near massive black holes (MBHs) lead to resonant angular momentum relaxation. Due to the fact that orbits are Keplerian to good approximation, the torques efficiently change the magnitude of the…
We compute gravitational waves from inspiraling stellar-mass compact objects on the equatorial plane of a massive spinning black hole (BH). Our inspiral orbits are computed by taking into account the adiabatic change of orbital parameters…
The nature of the gamma-ray burst (GRB) central engine still remains an enigma. Entities widely believed to be capable of powering the extreme jets are magnetars and black holes. The maximum rotational energy that is available in a…
Primordial black hole (PBH), which can be naturally produced in the early universe, remains a promising dark matter candidate . It can merge with a supermassive black hole (SMBH) in the center of a galaxy and generate gravitational wave…
The inspiral of a turbulent molecular cloud in the Galactic Centre may result in the formation of a small, dense and moderately eccentric gas disc around the supermassive black hole (SMBH). Such a disc is unstable to fragmentation and may…
Surveys with the Hubble Space Telescope find supermassive black holes (BHs) of 10**6 to 10**9.5 solar masses in every galaxy that has an elliptical-galaxy-like "bulge" component. BHs appear to be standard equipment in galaxy bulges. At the…
Gravitational waves (GWs) offer an unprecedented opportunity to survey the sky and detect mergers of compact objects. While intermediate-mass black holes (IMBHs) have not been detected beyond any reasonable doubt with either dynamical or…
The rate of accretion of matter from a solar-type star onto a primordial black hole (PBH) that passes through it is calculated. The probability that a PBH is captured into an orbit around a star in a galaxy is found. The mean lifetime of…
Black hole binaries with extreme ($\gtrsim 10^4:1$) or intermediate ($\sim 10^2-10^4:1$) mass ratios are among the most interesting gravitational wave sources that are expected to be detected by the proposed Laser Interferometer Space…
Maximum gravitational wave emission from binary stars in eccentric orbits occurs near the periastron passage. We show that for a stationary distribution of binary neutron stars in the Galaxy, several high-eccentricity systems with orbital…
The future space-based gravitational wave observatory, the Laser Interferometer Space Antenna, is expected to observe between 1-1000s extreme mass-ratio inspirals (EMRIs) per year. Due to the simultaneous presence of other gravitational…
We study the short-term effects of an intermediate mass black hole (IBH) on the orbit of star S2 (S02), the shortest-period star known to orbit the supermassive black hole (MBH) in the centre of the Milky Way. Near-infrared imaging and…
We study the orbital parameters distribution of stars that are scattered into nearly radial orbits and then spiral into a massive black hole (MBH) due to dissipation, in particular by emission of gravitational waves (GW). This is important…
We study eccentric equatorial orbits of a test-body around a Kerr black hole under the influence of gravitational radiation reaction. We have adopted a well established two-step approach: assuming that the particle is moving along a…
Fast radio bursts (FRBs) are millisecond-duration pulses of radio emission originating from extragalactic distances. Radio dispersion on each burst is imparted by intervening plasma mostly located in the intergalactic medium. We observe a…
The exploration of dark sector interactions via gravitational waves (GWs) from binary inspirals has been a subject of recent interest. We study dark forces using extreme mass ratio inspirals (EMRIs), pointing out two issues of interest.…
We make use of two empirical relations between the black hole mass and the global properties (bulge luminosity and stellar velocity dispersion) of nearby elliptical galaxies, to infer the mass of the central black hole (M_BH) in low…
A variety of arguments suggest that the most common form of gamma-ray bursts (GRBs), those longer than a few seconds, involve the formation of black holes in supernova-like events. Two kinds of ``collapsar'' models are discussed, those in…
Stellar-mass and supermassive black holes abound in the Universe, whereas intermediate-mass black holes (IMBHs) of ~10^2-10^5 solar masses in between are largely missing observationally, with few cases found only. Here we report the…
We study the number and interaction rates of supermassive black holes in galactic bulges as predicted by hierarchical models of galaxy formation in which the spheroidal components of galaxies are formed by mergers. In bright ellipticals,…