Related papers: Pair Drizzle around Sub-Eddington Supermassive Bla…
A time-dependent model for pair creation in a pulsar magnetosphere is developed. It is argued that the parallel electric field that develops in a charge-starved region (a gap) of a pulsar magnetosphere oscillates with large amplitude.…
The nature of the broad-band spectra of supermassive accreting black holes in active galactic nuclei (AGNs) is still unknown. The hard X-ray spectra of Seyferts as well as of Galactic stellar-mass black holes (GBHs) are well represented by…
An electron-positron atmosphere is inevitably created around a black hole accretion disc, the spectrum of which extends to MeV energies. Pairs created in photon-photon collisions outside the disc are blown away by soft radiation (which…
We use the public code ebhlight to carry out 3D radiative general relativistic magnetohydrodynamics (GRMHD) simulations of accretion onto the supermassive black hole in M87. The simulations self-consistently evolve a frequency-dependent…
We present a comprehensive analysis of four near-Eddington black hole accretion models computed by solving the GRMHD equations with full radiation transport. This study focuses on the dynamical effects of magnetic field topology and black…
We investigate the pair creation of magnetically charged black holes on a cosmic string in the presence of a background magnetic field. The string may either break or fray to produce a pair of accelerating black holes described by Ernst…
Generation of arbitrarily spin-polarized lepton (here refer in particular to electron and positron) beams has been investigated in the single-shot interaction of high-energy polarized $\gamma$ photons with an ultraintense asymmetric laser…
The pair-production process for a black hole (BH) is discussed within the framework of a recently proposed semiclassical model of BH evaporation. Our emphasis is on how the requirements of unitary evolution and strong subadditivity act to…
We suggest a formation scenario of black holes with intermediate mass $\sim 10^3 M_\odot$, by post recombination Bondi-Hoyle-Lyttleton accretion into ultra dense dark matter halos (UDMH) of $\sim 10^5 M_\odot$, which have formed around the…
Super-Eddington accretion discs with 3 and 15 dot M_E around black holes with mass 10 M_sun are examined by two-dimensional radiation hydrodynamical calculations extending from the inner disc edge to 5*10^4 r_g and lasting up to \sim 10^6…
The process of neutrino production of electron positron pairs in a magnetic field of arbitrary strength, where electrons and positrons can be created in the states corresponding to excited Landau levels, is analysed. The mean value of the…
The generation of relativistic jets in active sources such as blazars is a complex problem with many aspects, most of them still not fully understood. Relativistic jets are likely produced by the accretion of matter and magnetic fields onto…
We show that black holes supplied with mass at hyper--Eddington rates drive outflows with mildly sub--relativistic velocities. These are $\sim 0.1 - 0.2c$ for Eddington accretion factors $\dot m_{\rm acc} \sim 10 - 100$, and $\sim…
X-ray bright knots of kpc-scale jets of several radio loud quasars have been an actively discussed issue. Among various models to explain observations, synchrotron radiation from the electron population different from radio to IR emitting…
Recently, it was shown that the formation of a photon-trapping surface might not be sufficient to ensure unimpeded super-Eddington (SE) accretion. In light of this finding, here we derive a condition such that sustained and unimpeded SE…
Supermassive black holes are found at the centers of most galaxies and their inspiral is a natural outcome when galaxies merge. The inspiral of these systems is of utmost astrophysical importance as prodigious producers of gravitational…
Basic energy requirements of Gamma Ray Burst(GRB) sources can be easily accounted for by a pair creation process occurring in the "Dyadosphere" of a Black Hole endowed with an electromagnetic field (abbreviated to EMBH for "electromagnetic…
We investigate the conditions required for the production of electron-positron pairs above a pulsar polar cap (PC) and the influence of pair production on the energetics of the primary particle acceleration. Assuming space-charge limited…
We discuss a variety of bremsstrahlung processes associated with charged particles emitted by evaporating black holes. We show that such particles produce a negligible number of bremsstrahlung photons from their scattering off each other,…
We discuss a scheme of nonperturbative pair production by high energy photons ($\omega\gtrsim m$) in a strong external field achievable at the next high intensity laser experiments. The pair momentum is boosted and for $\omega\gtrsim 1.2m$…