Related papers: Pair Drizzle around Sub-Eddington Supermassive Bla…
We analyze the quantum process in which a cosmic string breaks in a de Sitter (dS) background, and a pair of neutral or charged black holes is produced at the ends of the string. The energy to materialize and accelerate the pair comes from…
We examine Poynting flux generation due to pair plasma accreting onto a slowly rotating black hole. In particular, we consider the possibility of an outgoing flux at the horizon. Our approach is based on a two-fluid model representing a…
Disc accretion on to a black hole is often misaligned from its spin axis. If the disc maintains a significant magnetic field normal to its local plane, we show that dipole radiation from Lense-Thirring precessing disc annuli can extract a…
We present the first collisionless realization of two-dimensional axisymmetric black hole accretion consistent with a persistent magnetically arrested disk state. The accretion flow, consisting of an ion-electron disk plasma combined with…
Super-Eddington accretion of neutron stars (NSs) has been suggested both observationally and theoretically. In this paper, we propose that NSs in close-orbit binary systems with companions of helium (He) stars, most of which systems form…
We investigate the process of creating electron-positron pairs from laser-matter interaction in pre-ionised foam targets using particle-in-cell simulations. A high-intensity laser pulse drives electrons via direct laser acceleration up to a…
We investigate the spontaneous pair production, including the Schwinger mechanism and the Hawking thermal radiation, of charged scalar particles from the near horizon region of a (near) extremal Reissner-Nordstr\"om black hole. The paradigm…
We discovered a simple regime where a near-critical plasma irradiated by a laser of experimentally available intensity can self-organize to produce positrons and accelerate them to ultra-relativistic energies. The laser pulse piles up…
Super-Eddington accretion onto massive black hole seeds may be commonplace in the early Universe, where the conditions exist for rapid accretion. Direct collapse black holes are often invoked as a possible solution to the observation of…
Electron-positron pair creation in collisions of a modulated laser pulse with a high-energy photon (nonlinear Breit-Wheeler process) is studied by means of strong-field quantum electrodynamics. It is shown that the driving pulse modulations…
The role of bremsstrahlung in the emission from hot accretion flows around slowly accreting supermassive black holes is not thoroughly understood. In order to appraise the importance of bremsstrahlung relative to other radiative processes,…
Two types of relativistic jets are suggested to form near accreting black holes: a potentially ultrarelativistic Poynting-dominated jet and a Poynting-baryon jet. One source of jet matter is electron-positron pair production, which is…
The processes of neutrino production of electron-positron pairs, $\nu \bar\nu \to e^- e^+$ and $\nu \to \nu e^- e^+$, in a magnetic field of arbitrary strength, where electrons and positrons can be created in the states corresponding to…
We evaluate several basic electrodynamic processes as modified by the presence of a very strong magnetic field, exceeding $B_{\rm Q} \equiv m^2/e = 4.4\times 10^{13}$ G. These results are needed to build models of dissipative phenomena…
We study the relativistically expanding electron-positron pair plasma formed by the process of vacuum polarization around an electromagnetic black hole (EMBH). Such processes can occur for EMBH's with mass all the way up to $6\cdot…
The photon spectrum emitted by a transrelativistic pair plasma is calculated in the presence of an ultrastrong magnetic field, and is shown to bear a remarkable resemblance to the rising hard X-ray spectra of quiescent magnetars. This…
We investigate the pair production near a (near) extremal magnetized Reissner-Nordstrom black hole. The pair production is shown to exist in the extremal state, which can be interpreted as the Schwinger effect due to the strong field under…
Binary black hole (BBH) mergers provide a prime source for current and future interferometric GW observatories. Massive BBH mergers may often take place in plasma-rich environments, leading to the exciting possibility of a concurrent…
We study very-high rate spherically symmetric accretion flows onto a massive black hole (BH; 10^2 < M_BH < 10^6 Msun) embedded in a dense gas cloud with a low abundance of metals, performing one-dimensional hydrodynamical simulations which…
The propagation of high energy (HE, $E_\gamma>100$ MeV) and very high-energy gamma-rays (VHE, $E_\gamma>100$ GeV) in the extra-galactic photon field leads to pair-production and consequently energy- and distance-dependent attenuation of the…