F (R) gravity after the detection of the orbital precession of the S2 star around the Galactic Center massive black hole

The GRAVITY Collaboration achieved a remarkable detection of the orbital precession of the S2 star around the Galactic Center supermassive black hole, providing yet another proof of the validity of general relativity. The departure from the Schwarzschild precession is encoded in the parameter fSP, which multiplies the predicted general relativistic precession. This parameter results in fSP=1.10±0.19, which is consistent with general relativity (fSP=1) at 1σ level. Nevertheless, this parameter may also hide an effect of the modified theories of gravity. Thus, we consider the orbital precession due to the Yukawa-like gravitational potential arising in the weak field limit of f(R)-gravity, and we use the current bound on the fSP to constrain the strength and the scale length of the Yukawa-like potential. No deviations from general relativity are revealed at the scale of λ<6300 AU with the strength of the Yukawa potential restricted to δ=-0.01-0.14+0.61.