Related papers: Magnetic Penrose process in the magnetized Kerr sp…
Comparable-mass black-hole mergers generically result in moderate to highly spinning holes, whose spacetime curvature will significantly affect nearby matter in observable ways. We investigate how the moderate spin of a post-merger Kerr…
Recently, Ruffini et al. [Phys. Rev. Lett. 134 (2025) 8, 081403] pointed out that the repetitive Penrose process cannot drain the entire extractable energy of a Kerr black hole. In this Letter, we alternatively point out the charge of a…
We calculate the evolution of the prompt intrinsic Poynting power generated by merging black holes. Orbiting black holes induce rotation of the space-time. In a presence of magnetic field supported by an accretion disk outside of the orbit,…
We extend the work by Appl and Camenzind (1988) for special relativistic magnetohydrodynamic (MHD) jets, to fully general relativistic studies of the standing shock formation for accreting MHD plasma in a rotating, stationary and…
We re-examine the possibility that astrophysical jet collimation may arise from the geometry of rotating black holes and the presence of high-energy particles resulting from a Penrose process, without the help of magnetic fields. Our…
The increasing data set of precise observations of very energetic and collimated jets, with black hole (BH) as putative central engine, at different astrophysical scales and in various environments, should soon permit to discriminate and…
Magnetic reconnection process in the ergosphere is investigated for a relativistic plasma around a rotating non-Kerr black hole. For a rotating non-Kerr black hole immersed in magnetic field generated by an externally material,…
Highly spinning Kerr black holes with masses $M = 1 - 100\ M_{\odot}$ are subject to an efficient superradiant instability in the presence of bosons with masses $\mu \sim 10^{-10} - 10^{-12}\ {\rm eV}$. We observe that this matches the…
In this article, we study the superradiance of charged scalar fields on the sub-extremal Reissner-Nordstrom metric, a mechanism by which such fields can extract energy from a static spherically symmetric charged black hole. A geometrical…
Galaxy observations suggest that mergers of supermassive black hole binaries (SMBHBs) are rare events, with rates of order one per decade across the observable Universe. We present a framework to search for merging SMBHBs in pulsar timing…
Magnetic fields in black hole accretion disks are associated with processes of mass accretion and energy amplification. The contribution of the magnetic field due to the magnetic polarization of the material induces effects on the physical…
General relativity (GR) predicts the existence of black hole (BH). The rotating BH called as a Kerr Black hole and GR implies that there is an upper limit on the angular momentum per mass squared of black holes $\leq 1$, above which the…
We consider a head-on collision of two massive particles that move in the equatorial plane of an extremal Kerr black hole, which results in the production of two massless particles. Focusing on a typical case, where both of the colliding…
The neutrino-driven wind cooling phase of proto-neutron stars (PNSs) follows successful supernovae. Wind models without magnetic fields or rotation fail to achieve the necessary conditions for production of the third $r-$process peak, but…
Explicitly computed Penrose diagrams are plotted for a classical model of black hole formation and evaporation, in which black holes form by the accretion of infalling spherical shells of matter and subsequently evaporate by emitting…
Scattering of particles in the gravitational field of Kerr black holes is considered. It is shown that scattering energy of particles in the centre of mass system can obtain very large values not only for extremal black holes but also for…
As a complementary or companion process to the Blandford-Znajek mechanism for the rotational energy extraction from a Kerr black hole to serve as a viable model for the central engine of quasar, AGN and even GRB, the magnetic alignment…
Antiferromagnetic L1$_{0}$-type MnPt is a material with relatively simple crystal and magnetic structure, recently attracting interest due to its high N{\'{e}}el temperature and wide usage as a pinning layer in magnetic devices. While it is…
Using solar wind observation near PSP perihelions as constraints, we have investigated the parameters in various PFSS model methods. It's found that the interplanetary magnetic field extrapolation with source surface height $R_\mathrm{SS} =…
Let a particle move in the flat space-time under the action of the electric potential. If it decays to two fragments, the energy of debris can be larger than the original energy and, moreover, the efficiency of such a process can be…