I Researching Causal Structure in Classical GR for Graduate Course

hideelo
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I am currently taking graduate course in GR following Carroll and Wald and we just started covering causal structure. In all my years studying physics this has been the first time something made me stop and go "I would love to spend a decade on this". To me it's a perfect blend of well posed mathematical problems and fundamental questions about reality. However I don't know if this is still an active area of research. If anyone can shed any light on this I would really appreciate it.

[Moderator's note: edited for spelling of "causal".]
 
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As far as I know, there is some (but not a lot) activity in causal structure in classical GR.
For example, here are some papers by Minguzzi
http://arxiv.org/abs/0708.2070
http://arxiv.org/abs/gr-qc/0703128

In classical GR, maybe one can try to find ways to weaken the causality conditions to extend various theorems (e.g. singularity theorems).
In attempts to formulate quantum gravity, there is more activity (e.g. Sorkin's http://en.wikipedia.org/wiki/Causal_sets ; see also Dowker http://arxiv.org/abs/gr-qc/0508109 ).
 
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