摘要:

A conformal map between a special case of the Vaidya metric and a 2-fluid Schwarzschild atmosphere is given. The Bach tensor and the conformal map allow the definition of a new conserved current. This current provides a bound to radiated power. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301568

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

I argue that black hole entropy counts only those states of a black hole that can influence the outside, and attempt (with only partial success) to defend this claim against various objections, all but one coming from string theory. Implications for the nature of the Bekenstein bound are discussed, and in particular the case for a holographic principle is challenged. Finally, a generalization of black hole thermodynamics to “partial event horizons” in general spacetimes without black holes is proposed. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301569

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Matrix theory and the AdS/CFT correspondence provide nonperturbative holographic formulations of string theory. In both cases the finite N theories can be thought of as infrared regulated versions of flat space string theory in which removing the cutoff is equivalent to letting N go to infinity. In this paper we consider the nature of this limit. In both cases the holographic mapping becomes completely nonlocal. In matrix theory this corresponds to the growth of D0-brane bound states with N. For the AdS/CFT correspondence there is a similar delocalization of the holographic image of a system as N increases. In this case the limiting theory seems to require a number of degrees of freedom comparable to large N matrix quantum mechanics. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301570

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Quantum aspects of black holes represent an important testing ground for a theory of quantum gravity. The recent success of string theory in reproducing the Bekenstein-Hawking black hole entropy formula provides a link between general relativity and quantum mechanics via thermodynamics and statistical mechanics. Here we speculate on the existence of new and unexpected links between black holes and polymers and other soft-matter systems. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301571

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

There have been many attempts to understand the statistical origin of black-hole entropy. Among them, entanglement entropy and the brick wall model are strong candidates. In this paper we show a relation between entanglement entropy and the brick wall model: the brick wall model seeks the maximal value of the entanglement entropy. In other words, the entanglement approach reduces to the brick wall model when we seek the maximal entanglement entropy. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301572

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This contribution to the proceedings of the 1999 Canadian Conference on General Relativity and Relativistic Astrophysics is a brief exposition of earlier work, with Sumati Surya (hep-th/9805121) Amanda Peet (hep-th/9903213), addressing certain results in higher dimensional supergravity that are related to black hole no-hair theorems. Its purpose is to describe, in language appropriate for an audience of relativists, how these results can be related to the Maldacena conjecture (aka, the AdS/CFT correspondence). The end product may be taken as a new kind of quantitative evidence in support of the Maldacena conjecture. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301573

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

In contrast to asymptotically flat black hole solutions for which all horizons settle down rapidly to have the topology of a sphere, certain asymptotically anti-de Sitter black hole solutions have horizons with the topology of a higher genus surface. The fact that the nontrivial topology of these horizons is not hidden might appear to indicate that generalizations of topological censorship do not hold for such spacetimes. However, this is not the case: topological censorship holds in anti-de Sitter spacetimes. Specifically, we prove every causal curve with endpoints on scri can be deformed to a curve at scri. From this it follows that the genus of the black hole horizon is set by the large scale topology of the spacetime. Our results clarify the connection between topological censorship and the non-spherical horizon topologies of locally anti-de Sitter black holes. Furthermore, the proof making this connection is valid for any spacetime that satisfies the principle of topological censorship. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301574

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

By a trivial modification of Hawking’s well-known topology theorem for black holes, one can obtain a lower bound of4&pgr;(g−1)/−&Lgr;for the area of an apparent horizon of genusgin a vacuum spacetime with cosmological constant&Lgr;<0.We discuss a derivation in the special case of an apparent horizon at a moment of time symmetry, so that the horizon is a minimal surface. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301575

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This talk discusses general perturbations of the continuously self-similar critical solution of the gravitational collapse of a massless scalar field (the Roberts solution). The exact analysis of the perturbation equations reveals that there are no growing non-spherical perturbation modes. Formation of discretely self-similar structure by growing spherically symmetric modes is considered. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301576

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

The purpose of this contribution is to present the different classes of solutions that exist for self-similar spherically symmetric spacetimes with a perfect fluid as matter source. In particular, there is a class of ‘asymptotically Minkowski’ solutions that was discovered only recently. This class of solutions appears to be of relevance in the study of critical phenomena in spherically symmetric perfect-fluid collapse. The results presented here are part of an investigation [1,2], in which the work of Carr & Coley [3] has been combined with that of Goliath, Nilsson & Uggla [4,5]. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1301577

出版商:AIP    

年代:1999

数据来源: AIP