Related papers: Mechanical feedback effects on primordial black ho…
Primordial black holes (PBHs) have attracted intensive research interest as a promising candidate of dark matter. However, because of the Hawking radiation, the PBHs lighter than $10^{15}~\rm{g}$ have already evaporated before today. To…
We study the long-term evolution of the global structure of axisymmetric accretion flows onto a black hole (BH) at rates substantially higher than the Eddington value ($\dot{M}_{\rm Edd}$), performing two-dimensional hydrodynamical…
We perform three general-relativistic magnetohydrodynamic simulations of black hole accretion designed to test how sensitive results are to grid resolution in the jet region. The cases differ only in numerics, modelling the same physical…
The inward flow of matter through accretion disks is driven by MHD turbulence. Global general relativistic MHD simulations shed quantitative light on this process, revealing a number of aspects of accretion previously unrecognized. Among…
Rotating accretion flow may undergo centrifugal pressure mediated shock transition even in presence of various dissipative processes, such as viscosity and cooling mechanism. The extra thermal gradient force along the vertical direction in…
Mounting theoretical evidence suggests that black holes are subjected to the memory burden effect, implying that after certain time the information stored in them suppresses the decay rate. This effect opens up a new window for small…
We describe the most general nature of accretion and wind flows around a compact object and emphasize on the properties which are special to black hole accretion. The angular momentum distribution in the most general solution is far from…
Context. The Bondi spherical accretion solution has been used to model accretion onto compact objects in a variety of situations, from interpretation of observations to subgrid models in cosmological simulations. Aims. We aim to investigate…
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…
A recent understanding on how quantum effects may affect black-hole evolution opens new scenarios for dark matter, in connection with the presence of black holes in the very early universe. Quantum fluctuations of the geometry allow for…
A recent approach to simulating localized feedback from active galactic nuclei by Power et al. (2011) uses an accretion disc particle to represent both the black hole and its accretion disc. We have extrapolated and adapted this approach to…
We review the theory behind the formation of primordial black hole binaries and their merger rates. We consider the binary formation in the early and late Universe, emphasising the former as it gives the dominant contribution of the present…
We investigate the effect of inhomogeneity on primordial black hole formation in the matter dominated era. In the gravitational collapse of an inhomogeneous density distribution, a black hole forms if apparent horizon prevents information…
We present the results of our studies on accretion disks in the proximity of astrophysical black holes. These disks can be of varying degrees of opacity, geometrical shapes, sizes, and volumes. The central compact object is a Schwarzschild…
We study the ejection of winds from thin accretion discs around stellar mass black holes and the time evolution of these winds in presence of radiation field generated by the accretion disc. Winds are produced by radiation, thermal pressure…
The relativistic accretion rate of dark matter by a black hole is revisited. Under the assumption that the phase space density indicator, $Q=\rho_{\infty}/\sigma^3_{\infty}$, remains constant during the inflow, the derived accretion rate…
We investigates the effect of accretion of cosmic fluid on the evolution of Primordial Black Holes (PBHs) within the framework of Modified gravity theories. We consider a general form of the Hubble parameter, reflecting a general class of…
We investigate time-dependent inviscid hydrodynamical accretion flows onto a black hole using numerical simulations. We consider the accretion that consists of hot tenuous gas with low specific angular momentum and cold dense gas with high…
We explore the impact of the central black hole (BH) spin on the large-scale properties of the host galaxy, by considering radiative feedback. The BH spin determines the radiation pattern from the accretion disc, which directly imprints on…
Neutron stars inspiralling into a stellar envelope can accrete at rates vastly exceeding the Eddington limit if the flow develops pressures high enough to allow neutrinos to radiate the released gravitational energy. It has been suggested…