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marcus

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## Main Question or Discussion Point

Here are some papers on the covariant entropy bound conjectured by Raphael Bousso

http://arxiv.org/abs/hep-th/9905177

http://arxiv.org/abs/hep-th/9908070

http://arxiv.org/abs/hep-th/0305149

It would be a significant development if the conjectured bound could be proven to hold in LQC.

It looks like Ashtekar et al have done this or are able to do it, with a bit more work. This was just posted:

http://arxiv.org/abs/0805.3511

Abhay Ashtekar, Edward Wilson-Ewing

15 pages, 3 figures

(Submitted on 22 May 2008)

"We examine Bousso's covariant entropy bound conjecture in the context of radiation filled, spatially flat, Friedmann-Robertson-Walker models. The bound is violated near the big bang. However, the hope has been that quantum gravity effects would intervene and protect it. Loop quantum cosmology provides a near ideal setting for investigating this issue. For, on the one hand, quantum geometry effects resolve the singularity and, on the other hand, the wave function is sharply peaked at a quantum corrected but smooth geometry which can supply the structure needed to test the bound.

http://arxiv.org/abs/hep-th/9905177

http://arxiv.org/abs/hep-th/9908070

http://arxiv.org/abs/hep-th/0305149

It would be a significant development if the conjectured bound could be proven to hold in LQC.

It looks like Ashtekar et al have done this or are able to do it, with a bit more work. This was just posted:

http://arxiv.org/abs/0805.3511

**The covariant entropy bound and loop quantum cosmology**Abhay Ashtekar, Edward Wilson-Ewing

15 pages, 3 figures

(Submitted on 22 May 2008)

"We examine Bousso's covariant entropy bound conjecture in the context of radiation filled, spatially flat, Friedmann-Robertson-Walker models. The bound is violated near the big bang. However, the hope has been that quantum gravity effects would intervene and protect it. Loop quantum cosmology provides a near ideal setting for investigating this issue. For, on the one hand, quantum geometry effects resolve the singularity and, on the other hand, the wave function is sharply peaked at a quantum corrected but smooth geometry which can supply the structure needed to test the bound.

**We find that the bound is respected.**We suggest that the bound need not be an essential ingredient for a quantum gravity theory but may emerge from it under suitable circumstances."