According to the thermodynamical analogy in black hole physics, the entropy of a black hole in the Einstein theory of gravity equals S BH = A H /(4l 2 P), where A H is the area of a black hole surface and l P = (¯ hG/c 3) 1/2 is the Planck length [1, 2]. In black hole physics the Bekenstein-Hawking entropy S BH plays essentially the same role an in the usual thermodynamics. In particular it all...

B holes are among the strangest predictions of Einstein’s general theory of relativity: regions of spacetime in which gravity is so strong that nothing—not even light—can escape. More precisely, a black hole is a singularity in spacetime surrounded by an event horizon, a surface that acts as a perfect one-way membrane: matter and radiation can enter the event horizon, but, once inside, can neve...

By using the brick wall method we calculate the thermodynamic potential of the complex scalar field in a charged Kerr black hole. Using it we show that in the Hartle-Hawking state the leading term of the entropy is proportional to AH ǫ , which becomes divergent as the system approaches the black hole horizon. The origin of the divergence is that the density of states diverges at the horizon. PA...

The scattering process of two particles at Planck energies or beyond is calculated using the gravitational shock wave metric for a massive black hole. Then, the scattering between a heavy mass particle and a small mass one is deal with. The cross section contains an extra new term of σ ∝ G3 as the correction term of the leading term derived by ’t Hooft. The ultrarelativistic limit of the Lorent...

The transformation of the SL(2, R)/U (1) black hole under a boost of the subgroup U (1) is studied. It is found that the tachyon vertex operators of the black hole go into those of the c = 1 conformal field theory coupled to gravity. The discrete states of the black hole also tend to the discrete states of the 2-d gravity theory. The fate of the extra discrete states of the black hole under boo...

A novel approach is described towards a microscopic understanding of the BekensteinHawking entropy of the simplest black hole – the Schwarzschild black hole. It is based at an intermediate step on the description of the black hole in terms of dual Euclidean brane/anti-brane pairs of type-IIB string-theory. By counting specific chain structures on the brane-complex one can reproduce the correct ...

We construct a supersymmetric rotating black hole with asymptotically flat four-dimensional spacetime times a circle, by superposing an infinite number of BMPV black hole solutions at the same distance in one direction. The near horizon structure is the same as that of the five-dimensional BMPV black hole. The rotation of this black hole can exceed the Kerr bound in general relativity (q ≡ a/G4...

Neutron star-black hole binaries are among the strongest sources of gravitational waves detectable by current observatories. They can also power bright electromagnetic signals (gamma-ray bursts, kilonovae), and may be a significant source of production of r-process nuclei. A misalignment of the black hole spin with respect to the orbital angular momentum leads to precession of that spin and of ...

We evaluate the Brownian motion of a massive particle (“black hole”) at the center of a galaxy using Nbody simulations. Our galaxy models have power-law central density cusps like those observed at the centers of elliptical galaxies. The simulations show that the black hole achieves a steady-state kinetic energy that is substantially different than would be predicted based on the properties of ...

We investigate giant and dual giant type BPS configurations in the nearhorizon geometry of a certain 1 16 -BPS AdS5 black hole. By quantising the space of solutions we count the dual giant configurations and compare with the black hole entropy. This suggests a missing degeneracy factor which we argue comes from an angular momentum quantum number. From the D-brane world volume this arises from B...