Black hole motion in Euclidean space as a diffusion process

A diffusion equation for a black hole is derived from the Bunster-Carlip equations. Its solution has the standard form of a Gaussian distribution. The second moment of the distribution determines the quantum of black hole area. The entropy of diffusion process is the same, apart from the logarithmic corrections, as the Bekenstein-Hawking entropy.Comment: 6 pages, no figures; v.2: a mistake in deriving of the diffusion equation corrected; a relation between the entropy of diffusion process and the Bekenstein-Hawking entropy correcte

Quantization of the black hole area as quantization of the angular momentum component

In transforming from Schwarzschild to Euclidean Rindler coordinates the Schwarzschild time transforms to a periodic angle. As is well-known, this allows one to introduce the Hawking temperature and is an origin of black hole thermodynamics. On the other hand, according to quantum mechanics this angle is conjugate to the $z$ component of the angular momentum. From the commutation relation and quantization condition for the angular momentum component it is found that the area of the horizon of a Schwarzschild black hole is quantized with the quantum $\Delta A = 8\pi l_P^{2}$. It is shown that this conclusion is also valid for a generic Kerr-Newman black hole.Comment: 4 pages (revtex), no figures; a boundary condition for the differential equation (15) added; the absent of the remnants in the approach noted; a reference added; accepted by Physical Review D for publicatio

What is the maximum rate at which entropy of a string can increase?

According to Susskind, a string falling toward a black hole spreads exponentially over the stretched horizon due to repulsive interactions of the string bits. In this paper such a string is modeled as a self-avoiding walk and the string entropy is found. It is shown that the rate at which information/entropy contained in the string spreads is the maximum rate allowed by quantum theory. The maximum rate at which the black hole entropy can increase when a string falls into a black hole is also discussed.Comment: 11 pages, no figures; formulas (18), (20) are corrected (the quantum constant is added), a point concerning a relation between the Hawking and Hagedorn temperatures is corrected, conclusions unchanged; accepted by Physical Review D for publicatio