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ranyart
Dec23-03, 07:12 AM
There has been an increase in the resolution of 'singularities'and the problems it brings.

here is a link to a very "average" paper at present. The authors(no relation to ''Jeff'' I hope! seem to be grasping in the dark?

Nevertheless, issue's are trying to be tackled from a number of interesting viewpoints, I am not being unreasonably here in my overview of the Paper or its authors, but it does appear to be a brave step, wether it turns out to be a step forward is another thing.

The authors appear to be from the "smolin school of exelance" Perimiter Institute.

http://uk.arxiv.org/PS_cache/gr-qc/pdf/0312/0312094.pdf

marcus
Dec23-03, 12:57 PM
This seems like a valuable paper. Thanks for the link!
Here is the abstract in case anyone wants to look
at that before downloading the PDF.

http://arxiv.org/gr-qc/0312094

As I see it the main thing this paper does is corroborate
Bojowald's results and make them more reliable.
I guess the word is "robust"

Bojowald showed if you use the connection variable approach
of Loop gravity and quantize the standard classical model of
cosmology, then the Big Bang singularity goes away.

This result has attracted a lot of attention over the past 3 years
and several other authors have confirmed it using basically the
same (Loop) approach.

But one can ask "Does this depend on using the connection variables
(the Ashtekar new variables for GR) or would it also work using
the earlier ADM variables?"

How tough and adaptible is the no-BB-singularity result? Will it carry over to different styles of formalism, different quantizations of different classical models? Does removing the BB singularity work in other quantizations of GR, or only in Loop?

These people (Viqar Husain and Oliver Winkler) asked this natural question and went and tried it. And indeed the no-singularity result turned out to be robust!

This does not mean that one would want to go back to using the metric, or go back to 1960-1970 (geo) metric dynamics. The connection variables approach seems more convenient. But it means one can place additional reliance on Bojowald's results. this is neat! Glad to see this paper ranyart, thanks again!