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marcus
Jan26-11, 07:25 PM
I'm hoping there will be some comment on this new paper of Kirill Krasnov

http://arxiv.org/abs/1101.4788
Gravity as a diffeomorphism invariant gauge theory
Kirill Krasnov
24 pages
(Submitted on 25 Jan 2011)
"A general diffeomorphism invariant SU(2) gauge theory is a gravity theory with two propagating polarisations of the graviton. We develop this description of gravity, in particular for future applications to the perturbative quantisation. Thus, the linearised theory, gauge symmetries, gauge fixing are discussed in detail, and the propagator is obtained. The propagator takes a simple form of that of Yang-Mills theory with an additional projector on diffeomorphism equivalence classes of connections inserted. In our approach the gravitational perturbation theory takes a rather unusual form in that the Planck length determined from the self-coupling of the graviton is no longer fundamental but becomes a derived quantity."

It is the latest in a series of paper going back to 2006 or 2007. MTd2 called it especially to our attention. He may have a handle on the cosmological constant.

Have to go out, I'll get back to this later.

MTd2
Jan26-11, 07:37 PM
Thanks marcus. But it was you that pointed out the paper. I just asked you privately to open the thread as this subject is not very known to me. :bigrin: