- #1

- 24,775

- 792

http://arxiv.org/abs/gr-qc/0504029

Abhay Ashtekar, Martin Bojowald

18 pages, 4 figures

IGPG04/8-4, AEI-2004-072

"A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: i) resolution of the Schwarzschild singularity in loop quantum gravity; and ii) time-evolution of black holes in the dynamical horizon framework. Quantum geometry effects introduce a major modification in the traditional space-time diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on space-time geometry and structure of quantum theory would be resolve."

this paper studies black hole evaporation under the arbitrary assumption that the future does not fork at a black hole-----no new universe with a new future is formed. Ashtekar and Bojowald make it clear that this is an assumption, not a conclusion.

"...the article, we will focus on this scenario. A space-time diagram that could result in scenario b) is depicted in figure 2. Here, the extended, ‘quantum space-time’ has a

the CGHS model here refers to some 1992 work by Strominger and others.

**Black hole evaporation: A paradigm**Abhay Ashtekar, Martin Bojowald

18 pages, 4 figures

IGPG04/8-4, AEI-2004-072

"A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: i) resolution of the Schwarzschild singularity in loop quantum gravity; and ii) time-evolution of black holes in the dynamical horizon framework. Quantum geometry effects introduce a major modification in the traditional space-time diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on space-time geometry and structure of quantum theory would be resolve."

this paper studies black hole evaporation under the arbitrary assumption that the future does not fork at a black hole-----no new universe with a new future is formed. Ashtekar and Bojowald make it clear that this is an assumption, not a conclusion.

"...the article, we will focus on this scenario. A space-time diagram that could result in scenario b) is depicted in figure 2. Here, the extended, ‘quantum space-time’ has a

**single asymptotic region in the future**, i.e.,**there are no ‘baby universes’. This is an assumption.**It is motivated by two considerations: i) the situation in the CGHS model where detailed calculations are possible and show that the quantum space-time has this property; and ii) experience with the action of the Hamiltonian constraint in the spherically symmetric midi-superspace in 4 dimensions.**However, only detailed calculations can decide whether this assumption is correct.**the CGHS model here refers to some 1992 work by Strominger and others.

Last edited: