Bi-gravity with a single graviton

  title={Bi-gravity with a single graviton},
  author={Sergei Yu. Alexandrov and Simone Speziale},
  journal={Journal of High Energy Physics},
We analyze a bi-gravity model based on the first order formalism, having as fundamental variables two tetrads but only one Lorentz connection. We show that on a large class of backgrounds its linearization agrees with general relativity. At the non-linear level, additional degrees of freedom appear, and we reveal the mechanism hiding them around the special backgrounds. We further argue that they do not contain a massive graviton, nor the Boulware-Deser ghost. The model thus propagates only one… Expand
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