Charged Black Hole Background Research Articles

Bekenstein bound, holography and brane cosmology in charged black hole backgrounds

We obtain a Bekenstein entropy bound for charged objects in arbitrary dimensions (D ≥ 4) using the D-bound recently proposed by Bousso. With the help of thermodynamics of conformal field theories corresponding to anti-de sitter (AdS) Reissner–Norström (RN) black holes, we discuss the relation between the Bekenstein and Bekenstein–Verlinde bounds. In particular, we propose a Bekenstein–Verlinde-like bound for the charged systems. In the Einstein–Maxwell theory with a negative cosmological constant, we discuss the brane cosmology with positive tension using the Binetruy–Deffayet–Langlois approach. The resulting Friedman–Robertson–Walker equation can be identified with the one obtained by the moving domain wall approach in the AdS RN black hole background. Finally we also address the holographic property of the brane universe.

Quantum entropy of two-dimensional extreme charged dilaton black hole

By using Hawking's treatment as well as Zaslavskii's treatment respectively and the brick wall model, two different values of classical entropy and quantum entropy of scalar fields in the two-dimensional extreme charged dilaton black hole backgrounds have been obtained. A new divergent term emerges in the quantum entropy under the extreme limit for Zaslavskii's treatment and its connection with the phase transition has been addressed.

Entropy and supersymmetry of D-dimensional extremal electric black holes versus string states

Following the work of Sen, we consider the correspondence between extremal black holes and string states in the context of the entropy. We obtain and study properties of electrically charged black hole backgrounds of tree level heterotic string theory compactified on a p-dimensional torus, for D = (10 − p) = 4,…,9. We study in particular a one-parameter extremal class of these black holes, the members of which are shown to be supersymmetric. We find that the entropy of such an extremal black hole, when calculated at the stringy stretched horizon, scales in such a way that it can be identified with the entropy of the elementary string state with the corresponding quantum numbers.