http://arxiv.org/PS_cache/arxiv/pdf/1111/1111.0301v1.pdf Hi everyone! I'd like to get a little discussion started on what you guys think about this paper if you have the time to read it. I find it really fascinating that they came to the conclusion that up-tunneling is impossible for Minkowski, DeSitter, or anti-de Sitter. They seem to have a very apt description of "down-tunelling" or going from something to nothing. They say that the main claim of their paper is that, "Nothing should be thought of as the limit of anti-de Sitter space in which the curvature length goes to zero." Do you think that they have provided substantial evidence for this claim and are there any problems you have found with the paper?