J. Mod. Phys. All (1996) 3331-3362. [hep-th/9505117]. [22] P. Creminelli, K. Hinterbichler, J. Khoury, A. Nicolis, and E. Trincherini, "Sublumina] Galilean Genesis" arXiv:1209.3768 [23] T L Curtright, "Potentials Unbounded Below" SIGMA 7 (2011) 042 (eprint: arXiv:1011.6056 [math-ph]) DOI: 10.3842/SIGMA.2011.04