Horava-Lifshitz gravity: tighter constraints for the Kehagias-Sfetsos solution from new solar system data

Abstract

We analytically work out the perturbation induced by the Kehagias-Sfetsos (KS) space-time solution of the Horava-Lifshitz (HL) modified gravity at long distances on the two-body range for a pair of test particles A and B orbiting the same mass M. We apply our results to the most recently obtained range-residuals δρfor some planets of the solar system (Mercury, Mars, Saturn) ranged from the Earth to effectively constrain the dimensionsless KS parameter ψ_0 for the Sun. We obtain ψ_0 >= 7.2 x 10^-10 (Mercury), ψ_0 >= 9 x 10^-12 (Mars), ψ_0 >= 1.7 x 10^-12 (Saturn). Such lower bounds are tighter than other ones existing in literature by several orders of magnitude. We also preliminarily obtain ψ_0 >= 8 x 10^-10 for the system constituted by the S2 star orbiting the Supermassive Black Hole (SBH) in the center of the Galaxy.

LaTex2e, 15 pages, 1 table, 3 figures, 31 references. Version matching the one at press in International Journal of Modern Physics D (IJMPD)