Estimating the Parameters of Extended Gravity Theories with the Schwarzschild Precession of S2 Star

Understand

After giving a short overview of previous results on constraining of Extended Gravity (EG) by stellar orbits, we discuss the Schwarzschild orbital precession of S2 star assuming the congruence with predictions of General Relativity (GR).

• At the moment, the S2 star trajectory is remarkably fitted with the first post-Newtonian (pN) approximation of GR.
• In particular, both Keck and VLT (GRAVITY) teams declared that the gravitational redshift near its pericenter passage for the S2 star orbit corresponds to theoretical estimates found with the first pN approximation.
• In 2020, the GRAVITY Collaboration detected the orbital precession of the S2 star around the supermassive black hole (SMBH) at the Galactic Center (GC) and showed that it is close to the GR prediction.