Galileon as a local modification of gravity

  title={Galileon as a local modification of gravity},
  author={Alberto Nicolis and Riccardo Rattazzi and Enrico Trincherini},
  journal={Physical Review D},
In the Dvali-Gabadadze-Porrati (DGP) model, the "self-accelerating" solution is plagued by a ghost instability, which makes the solution untenable. This fact, as well as all interesting departures from general relativity (GR), are fully captured by a four-dimensional effective Lagrangian, valid at distances smaller than the present Hubble scale. The 4D effective theory involves a relativistic scalar pi, universally coupled to matter and with peculiar derivative self-interactions. In this paper… 

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