Demystifier said:Can classical gravity be represented in the loop representation, analogously to LQG?
If yes, is it equivalent to the standard general relativity?
Corresponding references would be welcome.
As luck would have it, I was going back over some papers in your archived blog this afternoon that I wanted to re-read and that was one of them. The feeling that I took away from that paper was that independence from a fixed background would allow a relational theory of quantum gravity to exploit the concept of locality - something necessary to allow a dynamical theory of gravity.ccdantas said:The main arguments are summarized in Smolin's paper (http://arxiv.org/abs/hep-th/0507235) [Broken]. But, indeed, what you mention is a fundamental question and one should face the known difficulties in those approaches, and think over why one should go into that route.
Demystifier said:If anybody here knows the answer, then it is probably marcus.
Perhaps nobody says that QCD is nonlocal because nobody says that Willson loops are the ONLY meaningful physical quantities in QCD. But in LQG the situation seems to be different.Sauron said:And if we go further in the LQG canonical formalism we find that teh hilber space is defined in terms of holonomies (wilson loops) of the fields. Well, holonomies are nonlocal quantities undoubtly. But on one hand we have that Willson loops are an standard tecnique in latice QCD and i never have seem a claim that QCD is non local. Ad anyway, that would be the quantum part of the theory, not the classical.