Observational tests of quantum extension of Schwarzschild spacetime in loop quantum gravity with stars in the galactic center

TL;DR

This study tests the quantum extension of Schwarzschild spacetime predicted by loop quantum gravity using observational data of stars orbiting Sgr A*, finding no significant evidence but setting bounds on quantum gravity parameters.

Contribution

It introduces a method to test loop quantum gravity effects on stellar orbits by transforming geodesic equations into a perturbed Kepler problem and analyzing observational data.

Findings

No significant evidence of quantum-extended Schwarzschild black hole effects.

The S2 star provides the strongest bound on the LQG parameter $A_\lambda$, with an upper limit of 0.302.

The method constrains quantum gravity effects using stellar orbital data.

Abstract

In this paper, we use the publicly available observational data of 17 stellar stars orbiting Sgr A* to test the quantum extension of Schwarzschild spacetime in loop quantum gravity (LQG). For our purpose, we transform the geodesical evolution of a massive particle in the quantum-extended Schwarzschild black hole to the perturbed Kepler problem and calculate the effects of LQG on the pericentre advance of the stellar stars. With these effects, one is able to compare them with the publicly available astrometric and spectroscopic data of stellar stars in the galactic center. We perform Monte Carlo Markov Chain (MCMC) simulations to probe the possible LQG effects on the orbit of S-stars. No significant evidence of the quantum-extended Schwarzschild black hole from LQG is found. Among the posterior analyses of 17 S-stars, the result of S2 gives the strongest bound on the LQG parameter $A_\lambda$, which places an upper bound at 95\% confidence level on $A_\lambda$ to be $A_\lambda < 0.302$.