ar X iv : h ep - t h / 96 10 18 6 v 1 2 3 O ct 1 99 6 MODIFICATION OF BLACK - HOLE ENTROPY BY STRINGS

ar X iv : h ep - t h / 98 10 03 9 v 1 6 O ct 1 99 8 Remarks on Nöther charges and black holes en - tropy

We criticize and generalize some properties of Nöther charges presented in a paper by V. Iyer and R. M. Wald and their application to entropy of black holes. The first law of black holes thermodynamics is proven for any gauge-natural field theory. As an application charged Kerr-Newman solutions are considered. As a further example we consider a (1 + 2) black hole solution. 1

ar X iv : h ep - t h / 96 10 06 1 v 1 9 O ct 1 99 6 Stimulated emission of particles by 1 + 1 dimensional black holes ∗

The stimulated emission of massless bosons by a relativistic and the CGHS black hole are studied for real and complex scalar fields. The radiations induced by one-particle and thermal states are considered and their thermal properties investigated near the horizon. These exhibit both thermal and non-thermal properties for the two black-hole models.

ar X iv : h ep - t h / 96 10 03 1 v 1 7 O ct 1 99 6 INJE – TP – 96 – 5 Higher dimensional extremal black strings

We investigate the five and six-dimensional black strings within EinsteinMaxwell theory. The extremal black strings are endowed with the null Killing symmetry. We study the propagation of Einstein-Maxwell modes in the extremal black string background by using this symmetry. It turns out that one graviton is a propagating mode, while both the Maxwell(F) and three-form (H) fields are non-propagat...

ar X iv : h ep - t h / 96 10 08 6 v 1 1 1 O ct 1 99 6 Entropy of Localized States and Black Hole Evaporation ∗

We call a state “vacuum-bounded” if every measurement performed outside a specified interior region gives the same result as in the vacuum. We compute the maximum entropy of a vacuum-bounded state with a given energy for a one-dimensional model, with the aid of numerical calculations on a lattice. The maximum entropy is larger than it would be for rigid wall boundary conditions by an amount δS,...

ar X iv : h ep - t h / 96 10 18 5 v 1 2 3 O ct 1 99 6 A Functional Approach to the Heat Kernel in Curved Space