相关论文: Energy Extraction from the Einstein-Born-Infeld Bl…
In this report we describe quantum Reissner-Nordstr\"om (RN) black-holes interacting with a complex scalar field. Our analysis is characterized by solving a Wheeler-DeWitt equation in the proximity of an apparent horizon of the RN…
We evaluate the \emph{surface energy~(${\cal E}_{s}^{\pm}$), rotational energy~(${\cal E}_{r}^{\pm}$) and electromagnetic energy~(${\cal E}_{em}^{\pm}$)} for a \emph{Kerr-Sen black hole~(BH)} having the event horizon~(${\cal H}^{+}$) and…
The entropy of extremal black holes (BHs) is obtained using a continuity argument from extremal quasiblack holes (QBHs). It is shown that there exists a smooth limiting transition in which (i) the system boundary approaches the extremal…
In Einstein-Maxwell theory, magnetic flux lines are `expelled' from a black hole as extremality is approached, in the sense that the component of the field strength normal to the horizon goes to zero. Thus, extremal black holes are found to…
The Penrose process, a process that transfers energy from a black hole to infinity, together with the BSW mechanism, which uses collisions of ingoing particles at the event horizon of a black hole to locally produce large amounts of energy,…
Born-Infeld electrogravity is defined through a Lagrangian that couples gravity and electromagnetism within a single determinantal structure. The field equations are derived in Palatini's formalism, where the metric, connection, and vector…
We investigate the power of a collisional Penrose process with an unbound energy extraction from an extreme Reissner-Nordstr\"{o}m black hole. This process takes infinite time in a time coordinate at a constant radial coordinate outside of…
We show that the extremal Reissner-Nordstr\"{o}m type multi black holes in an emergent scenario are exact in General Relativity. It is shown that an axion in the bulk together with a geometric torsion ensure the required energy-momentum to…
It is shown that the Born--Infeld nonlinear electrodynamics with a polynomial type nonlinearity accommodates finite-energy electric point charges but rejects finite-energy magnetic point charges, or monopoles, thereby spelling out an…
We point out that in general the Reissner-Nordstr\"om (RN) charged black holes of general relativity are not solutions of the four dimensional quadratic gravitational theories. They are, e.g., exact solutions of the $R+R^2$ quadratic theory…
Based on the magnetic reconnection mechanism, this study investigates how to extract energy effectively from an accelerating Kerr black hole in the plunging region and circular orbit region. After introducing the properties of accelerating…
The Schwinger effect has a variety of physics applications. In the context of black hole physics, it provides a channel for the decay of charged black holes. While the Schwinger rate has been derived for extremal Reissner-Nordstr\"om (RN)…
Fundamental string theory has been used to show that low energy excitations of certain black holes are described by a two dimensional conformal field theory. This picture has been found to be extremely robust. In this paper it is argued…
Following Rosen's quantization rules, two of the Authors (CC and FF) recently described the Schwarzschild black hole (BH) formed after the gravitational collapse of a pressureless "star of dust" in terms of a "gravitational hydrogen atom".…
Magnetic reconnection within a highly magnetized plasma has been seen as a viable mechanism to extract the energy from a rotating black hole, as it can generate negative energy plasmoids in the ergoregion. For a typical accreting black…
We study the implications of an isentropic processes applied to a Reissner-Nordstr\"om black hole. This process is possible if a black hole absorbs a particle with a specific ratio of energy and charge. We show that such an absorption…
The possibility of mining the rotational energy from black holes has far--reaching implications. Such energy extraction could occur even for isolated black holes, if hypothetical ultralight bosonic particles exist in Nature, leading to a…
Following Barrow's idea of fractal black hole horizon, we re-derive black hole entropy of static spherically symmetric black holes. When a black hole absorbs matter its horizon area will increase. Given the spherically fractal structure, we…
Using sophisticated string theory calculations, Maldacena and Susskind have intriguingly shown that near-extremal black holes are characterized by a {\it finite} mass gap above the corresponding zero-temperature (extremal) black-hole…
We study the Hawking radiation of (4+n)-dimensional Schwarzschild black hole imbedded in the space-time with positive cosmological constant. The greybody and energy emission rates of scalars, fermions, bosons, and gravitons are calculated…