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marcus

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## Main Question or Discussion Point

This is a long-awaited paper.

http://www.arxiv.org/abs/gr-qc/0509075

Abhay Ashtekar, Martin Bojowald

31 pages, 1 figure

IGPG-05-09/01, AEI-2005-132

"In homogeneous cosmologies, quantum geometry effects lead to a resolution of the classical singularity without having to invoke special boundary conditions at the singularity or introduce ad-hoc elements such as unphysical matter. The same effects are shown to lead to a resolution of the Schwarzschild singularity. The resulting quantum extension of space-time is likely to have significant implications to the black hole evaporation process. Similarities and differences with the situation in quantum geometrodynamics are pointed out."

SAMPLE FROM CONCLUSIONS SECTION

"Results of the last two sections support a general scenario that has emerged from the analysis of singularities in quantum cosmology. It suggests that

In the past, Ashtekar has been cautious about broaching this possibility. IIRC about a year ago he gave a seminar talk about LQG quantum black hole and his work with Bojowald. The two later published a paper on BH evaporation ( http://www.arxiv.org/abs/gr-qc/0504029 ) which was worded in a very reserved way.

In this paper he comes closer to saying that spacetime might re-expand from the pit of a black hole, forming another tract of the universe by another bang. In my view, he still does not say this unreservedly. There is another paper in the works, reference [10], with Parampreet Singh.

http://www.arxiv.org/abs/gr-qc/0509075

**Quantum geometry and the Schwarzschild singularity**Abhay Ashtekar, Martin Bojowald

31 pages, 1 figure

IGPG-05-09/01, AEI-2005-132

"In homogeneous cosmologies, quantum geometry effects lead to a resolution of the classical singularity without having to invoke special boundary conditions at the singularity or introduce ad-hoc elements such as unphysical matter. The same effects are shown to lead to a resolution of the Schwarzschild singularity. The resulting quantum extension of space-time is likely to have significant implications to the black hole evaporation process. Similarities and differences with the situation in quantum geometrodynamics are pointed out."

SAMPLE FROM CONCLUSIONS SECTION

"Results of the last two sections support a general scenario that has emerged from the analysis of singularities in quantum cosmology. It suggests that

**the classical singularity does not represent a final frontier; the physical space-time does not end there**. In the Planck regime, quantum fluctuations do indeed become so strong that the classical description breaks down. The space-time continuum of classical general relativity is replaced by discrete quantum geometry which remains regular during the transition through what was a classical singularity. Certain similarities between the Kantowski-Sachs model analyzed here and a cosmological model which has been studied in detail [10] suggest that there would be**a quantum bounce**to another large classical region. If this is borne out by detailed numerical calculations, one would conclude that quantum geometry in**the Planck regime serves as a bridge between two large classical regions.**Space-time may be much larger than general relativity has had us believe."In the past, Ashtekar has been cautious about broaching this possibility. IIRC about a year ago he gave a seminar talk about LQG quantum black hole and his work with Bojowald. The two later published a paper on BH evaporation ( http://www.arxiv.org/abs/gr-qc/0504029 ) which was worded in a very reserved way.

In this paper he comes closer to saying that spacetime might re-expand from the pit of a black hole, forming another tract of the universe by another bang. In my view, he still does not say this unreservedly. There is another paper in the works, reference [10], with Parampreet Singh.

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