Orbital precession of the S2 star in Scalar–Tensor–Vector Gravity
Riccardo Della Monica, Ivan De Martino, Mariafelicia De Laurentis
Abstract
ABSTRACT We have obtained the first constraint of the parameter space of Scalar–Tensor–Vector Gravity using the motion of the S2-star around the supermassive black hole at the centre of the Milky Way, and we did not find any serious tension with General Relativity. We used the Schwarzschild-like metric of Scalar–Tensor–Vector Gravity to predict the orbital motion of S2-star, and to compare it with the publicly available astrometric data, which include 145 measurements of the positions, 44 measurements of the radial velocities of S2-star along its orbit, and only the inferred rate of precession, as the latest GRAVITY data are not yet public. We employed a Markov chain Monte Carlo algorithm to explore the parameter space, and constrained the only one additional parameter of Scalar–Tensor–Vector Gravity to α ≲ 0.662 at 99.7 ${{\ \rm per\ cent}}$ confidence level, where α = 0 reduces this modified theory of gravity to General Relativity.