Solar System tests of Hořava–Lifshitz gravity

In the present paper, we consider the possibility of observationally constraining Hořava gravity at the scale of the Solar System, by considering the classical tests of general relativity (perihelion precession of the planet Mercury, deflection of light by the Sun and the radar echo delay) for the spherically symmetric black hole Kehagias–Sfetsos solution of Hořava–Lifshitz gravity. All these gravitational effects can be fully explained in the framework of the vacuum solution of Hořava gravity. Moreover, the study of the classical general relativistic tests also constrains the free parameter of the solution. From the analysis of the perihelion precession of the planet Mercury, we obtain for the free parameter ω of the Kehagias–Sfetsos solution the constraint ω ≥3.212×10 −26 cm −2 , the deflection of light by the Sun gives ω ≥4.589×10 −26 cm −2 , while the radar echo delay observations can be explained if the value of ω satisfies the constraint ω ≥9.179×10 −26 cm −2 .