- #1
- 24,775
- 792
http://arxiv.org/abs/0901.0640
Horizons and the cosmological constant
Krzysztof A. Meissner
6 pages
(Submitted on 6 Jan 2009)
"A new solution of the Einstein equations for the point mass immersed in the de Sitter Universe is presented. The properties of the metric are very different from both the Schwarzschild black hole and the de Sitter Universe: it is everywhere smooth, light can propagate outward through the horizon, there is an antitrapped surface enclosing the point mass and there is necessarily an initial singularity. The solution for any positive cosmological constant is qualitatively different from the Schwarzschild solution and is not its continuous deformation."
SAMPLE QUOTE:
"4. Conclusions
In the paper we have shown that the solution of the Einstein equations (5) for a point mass immersed in the universe with the positive cosmological constant has very special properties: the metric is everywhere smooth, light can propagate outward through the horizon, there is an antitrapped surface enclosing the point mass and there is necessarily an initial singularity. Although with extremely small value of H such an object for all practical purposes looks like a usual black hole the conceptual difference resulting from the fact that there is no horizon for the outward propagation of light can be far-reaching
– first, one should rethink a notion of a black hole entropy as proportional to the area of the horizon and second, there seems to be no information loss even classically since the communication of the inside with the outside is extremely weak but nonvanishing.
It is also interesting to note that in the presence of such objects there is necessarily an initial singularity in distinction to the pure de Sitter universe and there is no continuous deformation connecting Λ > 0 solution described in this paper and the Schwarzschild metric."
What interests me here is how this deSitter black hole solution will serve as a basis for LQG research. We know of Chris Meissner already from his LQG papers:
arXiv:gr-qc/0509049
Eigenvalues of the volume operator in loop quantum gravity
Krzysztof A. Meissner
12 pages, Class.Quant.Grav. 23 (2006) 617-626
arXiv:gr-qc/0407052
Black hole entropy in Loop Quantum Gravity
Krzysztof A. Meissner
10 pages, Class.Quant.Grav. 21 (2004) 5245-5252
And there is already a considerable number of papers using LQG to resolve the black hole singularity---typically finding a bounce. Now I'm wondering what will happen when the same researchers go after this new solution, a black hole in a universe with positive cosmological constant.
One could argue that this solution of Meissner's has added realism at least in the sense that the universe does seem to have a positive cosmological constant. In that case, according to Meissner, there is no horizon. Light carrying information can gradually escape from the interior. This is not the same as the thermal Hawking radiation originating just outside the horizon.
Horizons and the cosmological constant
Krzysztof A. Meissner
6 pages
(Submitted on 6 Jan 2009)
"A new solution of the Einstein equations for the point mass immersed in the de Sitter Universe is presented. The properties of the metric are very different from both the Schwarzschild black hole and the de Sitter Universe: it is everywhere smooth, light can propagate outward through the horizon, there is an antitrapped surface enclosing the point mass and there is necessarily an initial singularity. The solution for any positive cosmological constant is qualitatively different from the Schwarzschild solution and is not its continuous deformation."
SAMPLE QUOTE:
"4. Conclusions
In the paper we have shown that the solution of the Einstein equations (5) for a point mass immersed in the universe with the positive cosmological constant has very special properties: the metric is everywhere smooth, light can propagate outward through the horizon, there is an antitrapped surface enclosing the point mass and there is necessarily an initial singularity. Although with extremely small value of H such an object for all practical purposes looks like a usual black hole the conceptual difference resulting from the fact that there is no horizon for the outward propagation of light can be far-reaching
– first, one should rethink a notion of a black hole entropy as proportional to the area of the horizon and second, there seems to be no information loss even classically since the communication of the inside with the outside is extremely weak but nonvanishing.
It is also interesting to note that in the presence of such objects there is necessarily an initial singularity in distinction to the pure de Sitter universe and there is no continuous deformation connecting Λ > 0 solution described in this paper and the Schwarzschild metric."
What interests me here is how this deSitter black hole solution will serve as a basis for LQG research. We know of Chris Meissner already from his LQG papers:
arXiv:gr-qc/0509049
Eigenvalues of the volume operator in loop quantum gravity
Krzysztof A. Meissner
12 pages, Class.Quant.Grav. 23 (2006) 617-626
arXiv:gr-qc/0407052
Black hole entropy in Loop Quantum Gravity
Krzysztof A. Meissner
10 pages, Class.Quant.Grav. 21 (2004) 5245-5252
And there is already a considerable number of papers using LQG to resolve the black hole singularity---typically finding a bounce. Now I'm wondering what will happen when the same researchers go after this new solution, a black hole in a universe with positive cosmological constant.
One could argue that this solution of Meissner's has added realism at least in the sense that the universe does seem to have a positive cosmological constant. In that case, according to Meissner, there is no horizon. Light carrying information can gradually escape from the interior. This is not the same as the thermal Hawking radiation originating just outside the horizon.
Last edited: