Geodesics and periodic orbits in Kehagias-Sfetsos black holes in deformed Horava-Lifshitz gravity

The motion of a massive test particle around a Kehagias-Sfetsos black hole in deformed Horava-Lifshitz gravity is studied. Employing the effective potential, the marginally bound orbits and the innermost stable circular orbits are analyzed. For the marginally bound orbits, their radius and angular momentum decrease with the parameter omega of the gravity. For the innermost stable circular orbits, the energy and angular momentum also decrease with omega. Based on these results, we investigate the periodic orbits in the Kehagias-Sfetsos black holes. It is found that the apsidal angle parameter increases with the particle energy, while it decreases with the angular momentum. Moreover, compared to the Schwarzschild black hole, the periodic orbits in Kehagias-Sfetsos black holes always have lower energy. These results provide us a possible way to distinguish the Kehagias-Sfetsos black hole in deformed Horava-Lifshitz gravity from the Schwarzschild black hole.