Twistorial structure of loop-gravity transition amplitudes

@article{Speziale2012TwistorialSO,
  title={Twistorial structure of loop-gravity transition amplitudes},
  author={Simone Speziale and Wolfgang Wieland},
  journal={Physical Review D},
  year={2012},
  volume={86},
  pages={124023}
}
The spin foam formalism provides transition amplitudes for loop quantum gravity. Important aspects of the dynamics are understood, but many open questions are pressing on. In this paper we address some of them using a twistorial description, which brings new light on both classical and quantum aspects of the theory. At the classical level, we clarify the covariant properties of the discrete geometries involved, and the role of the simplicity constraints in leading to SU(2) Ashtekar-Barbero… 

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