Constraints on RnRn gravity from precession of orbits of S2-like stars: A case of a bulk distribution of mass

Here we investigate possible applications of observed stellar orbits around Galactic Center for constraining the Rn gravity at Galactic scales. For that purpose, we simulated orbits of S2-like stars around the massive black hole at Galactic Center, and study the constraints on the Rn gravity which could be obtained by the present and next generations of large telescopes. Our results show that Rn gravity affects the simulated orbits in the qualitatively similar way as a bulk distribution of matter (including a stellar cluster and dark matter distributions) in Newton’s gravity. In the cases where the density of extended mass is higher, the maximum allowed value of parameter ββ in Rn gravity is noticeably smaller, due to the fact that the both extended mass and RnRn gravity cause the retrograde orbital precession.