Master Constraint and canonical LQG

[ensabah6]

So Thieman and co are still working on the Master Constraint program for canonical, non-SF, LQG?

I thought that approach was dead and given way to SF ala Rovelli

 

[atyy]

Looks like they are relating it to spin foams.

http://arxiv.org/abs/0911.3428
"The corrections are especially severe if the theory suffers from second class secondary constraints. In a companion paper we compute these corrections for the Holst and Plebanski formulations of GR on which current spin foam models are based. "

http://arxiv.org/abs/0911.3431
"Then the Master Constraint DID for those Abelian constraints can be directly related to the Rigging Map and therefore has a path integral formulation. "

Maybe they will make tom.stoer happy?

 

[MTd2]

The weird thing here it is that Marcus did not open a thread with over 9000 insightful posts...

 

[tom.stoer]

I think Thiemann is doing what I expected to be relevant for both canonical and PI QG. Either relate the canonical approach to spin foams and proof equivalence - or demonstrate where and why this fails.

Thiemann writes "Path integral formulations for gauge theories must start from the canonical formulation in order to obtain the correct measure." I fully agree with him. For me any path integral is always a derived object.