gr-qc/0604072 [abs, ps, pdf, other] :

Title: Information-preserving black holes still do not preserve baryon number and other effective global quantum numbers

Authors: Dejan Stojkovic, Glenn D. Starkman, Fred C. Adams

Comments: Honorable Mention on Gravity Essay Competition 2005; Published in the special Essay issue of Int.J.Mod.Phys

Journal-ref: Int.J.Mod.Phys.D14:2293-2300,2005

It has been claimed recently that the black hole information-loss paradox has been resolved: the evolution of quantum states in the presence of a black hole is unitary and information preserving. We point out that, contrary to some claims in literature, information-preserving black holes still violate baryon number and any other quantum number which follows from an effective (and thus approximate) or anomalous symmetry.

http://arxiv.org/abs/gr-qc/0604072

gr-qc/0604074 [abs, ps, pdf, other] :

Title: The quantum black hole in 2+1 dimensions

Authors: B. Ram, J. Shirley

Comments: 5 pages, no figs

In this paper we investigate the quantum nature of a 2+1 dimensional black hole using the method [arXiv: gr-qc/0504030] which earlier revealed the quantum nature of a black hole in 3+1 dimensions.

http://arxiv.org/abs/gr-qc/0604074

hep-th/0604075 [abs, ps, pdf, other] :

Title: Escaping from the black hole?

Authors: E. Babichev, V. Mukhanov, A. Vikman

Comments: 4 pages, 2 figures

We show that if there exists a special kind of Born-Infeld type scalar field, then one can send information from inside a black hole. This information is encoded in perturbations of the field propagating in non-trivial scalar field backgrounds, which serves as a "new ether". Although the theory is Lorentz-invariant it allows, nevertheless, the superluminal propagation of perturbations with respect to the "new ether". We found the stationary solution for background, which describes the accretion of the scalar field onto a black hole. Examining the propagation of small perturbations around this solution we show the signals emitted inside the horizon can reach an observer located outside the black hole. We discuss possible physical consequences of this result.

http://arxiv.org/abs/hep-th/0604075