Loop-quantum-gravity vertex amplitude.

@article{Engle2007LoopquantumgravityVA,
  title={Loop-quantum-gravity vertex amplitude.},
  author={J S Engle and Roberto Pereira and Carlo Rovelli},
  journal={Physical review letters},
  year={2007},
  volume={99 16},
  pages={
          161301
        }
}
Spin foam models are hoped to provide the dynamics of loop-quantum gravity. However, the most popular of these, the Barrett-Crane model, does not have the good boundary state space and there are indications that it fails to yield good low-energy n-point functions. We present an alternative dynamics that can be derived as a quantization of a Regge discretization of Euclidean general relativity, where second class constraints are imposed weakly. Its state space matches the SO(3) loop gravity one… 
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