A new spin foam model for 4D gravity

@article{Freidel2007ANS,
  title={A new spin foam model for 4D gravity},
  author={Laurent Freidel and Kirill Krasnov},
  journal={Classical and Quantum Gravity},
  year={2007},
  volume={25},
  pages={125018}
}
Starting from Plebanski formulation of gravity as a constrained BF theory we propose a new spin foam model for 4D Riemannian quantum gravity that generalizes the well-known Barrett–Crane model and resolves the inherent to it ultra-locality problem. The BF formulation of 4D gravity possesses two sectors: gravitational and topological ones. The model presented here is shown to give a quantization of the gravitational sector, and is dual to the recently proposed spin foam model of Engle et al… 
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