nctional Equations" Phys.Rev. D83 (2011) 065019 (e-Print: arXiv:1010.5174 [hep-th]) DOI: 10.1103/PhysRevD.83.065019 [34] C. Deffayet, S. Deser, and G. Esposito-Farese, "Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors" Phys. Rev.