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

TL;DR

This paper derives constraints on the Kehagias-Sfetsos solution in Horava-Lifshitz gravity using solar system data, significantly tightening bounds on the model's parameters compared to previous studies.

Contribution

It provides the first analytical perturbation analysis of the KS solution's effects on two-body range, applying it to solar system data to set new, tighter constraints on the model.

Findings

Lower bounds on the KS parameter 7; 7; 7; for Mercury, Mars, Saturn, respectively.

Constraints are several orders of magnitude tighter than previous limits.

Preliminary bounds also obtained for the S2 star orbiting the Galactic Center.

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 \delta\rho for some planets of the solar system (Mercury, Mars, Saturn) ranged from the Earth to effectively constrain the dimensionsless KS parameter \psi_0 for the Sun. We obtain \psi_0 >= 7.2 x 10^-10 (Mercury), \psi_0 >= 9 x 10^-12 (Mars), \psi_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 \psi_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.