2011/08/31 by Tao Zhu, Qiang Wu, Anzhong Wang +1 · 1 citation
Physics and Astronomy · #hep-th #astro-ph.CO #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevd.84.101502
published as Phys.Rev. D84 (2011) 101502 · Revtex4, no figures. Some typos are corrected. Phys. Rev. D84, 101502 (R) (2011)
arxiv created 2013/01/07 · arxiv updated 2014/11/10
In this paper, we show that the spin-0 gravitons appearing in Horava-Lifshitz gravity without the projectability condition can be eliminated by extending the gauge symmetries of the foliation-preserving diffeomorphisms to include a local U(1) symmetry. As a result, the problems of stability, ghost, strong coupling, and different speeds in the gravitational sector are automatically resolved. In addition, with the detailed balance condition softly breaking, the number of independent coupling constants can be significantly reduced (from more than 70 down to 15), while the theory is still UV complete and possesses a healthy IR limit, whereby the prediction powers of the theory are considerably improved. The strong coupling problem in the matter sector can be cured by introducing an energy scale M*, so that M* < Λω, where M* denotes the suppression energy of high order derivative terms, and Λω the would-be strong coupling energy scale.