Relativistic effects in orbital motion of the S-stars at the Galactic Center

TL;DR

This paper investigates relativistic effects in the orbital motion of S-stars near the Galactic Center using PPN formalism and quantum-field gravity, constraining PPN parameters and confirming positive gravity energy density.

Contribution

It applies PPN and Post-Newtonian formalisms to S-star data, providing new constraints on PPN parameters and confirming positive gravity energy density.

Findings

PPN parameters β and γ are constrained using S-star data.

Positive gravity energy density component T_g^{00} is confirmed.

Relativistic pericenter shift is measurable in S-star orbits.

Abstract

The Galactic Center star cluster, known as S-stars, is a perfect source of relativistic phenomena observations. The stars are located in the strong field of relativistic compact object Sgr A* and are moving with very high velocities at pericenters of their orbits. In this work we consider motion of several S-stars by using the Parameterized Post-Newtonian (PPN) formalism of General Relativity (GR) and Post-Newtonian (PN) equations of motion of the Feynman's quantum-field gravity theory, where the positive energy density of the gravity field can be measured via the relativistic pericenter shift. The PPN parameters $\beta$ and $\gamma$ are constrained using the S-stars data. The positive value of the $T_g^{00}$ component of the gravity energy-momentum tensor is confirmed for condition of S-stars motion.