Observational test of ${\cal R}^{2}$ spacetimes with the S2 star in the Milky Way galactic center

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Yan, Jian-Ming, Zhu, Tao, Azreg-Aïnou, Mustapha, Jamil, Mubasher, Nguyen, Hoang Ky
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910559485558784
author Yan, Jian-Ming
Zhu, Tao
Azreg-Aïnou, Mustapha
Jamil, Mubasher
Nguyen, Hoang Ky
author_facet Yan, Jian-Ming
Zhu, Tao
Azreg-Aïnou, Mustapha
Jamil, Mubasher
Nguyen, Hoang Ky
contents A novel class of vacuum metrics expressible in analytical form was recently found for pure $\mathcal R^2$ gravity, based on a groundwork put forth by Buchdahl in 1962. These Buchdahl-inspired solutions offer a practical framework for testing ${\cal R}^2$ gravity through empirical observations. Within a subclass of asymptotically flat Buchdahl-inspired vacuum spacetimes, we identified a parameter $ε$ measuring the deviation from the classic Schwarzschild metric, which corresponds to $ε=0$. In this paper, we employ observational data from the S2 star's orbit around Sgr A* in the Milky Way galactic center and perform Monte Carlo Markov Chain simulations to probe the effects of the new metrics on the orbit of the S2 star. Our analysis presented herein reports a range at 95\% confidence level on the deviation parameter as $ε\in(-0.6690,\ 0.4452)$. While no decisive evidence either in favor or in disfavor of the asymptotically flat Buchdahl-inspired spacetimes has been achieved, the obtained bound is compatible with the tighter results using other data of different nature as recently reported in Eur.\,Phys.\,J.\,C $\bf 84$, 330 (2024). As a meaningful test probing into a strong-field regime, our present study calls for further observations with prolonged period and improved accuracy in order to tighten the bound for $ε$ using the S2 star orbit.
format Preprint
id arxiv_https___arxiv_org_abs_2405_10559
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Observational test of ${\cal R}^{2}$ spacetimes with the S2 star in the Milky Way galactic center
Yan, Jian-Ming
Zhu, Tao
Azreg-Aïnou, Mustapha
Jamil, Mubasher
Nguyen, Hoang Ky
General Relativity and Quantum Cosmology
A novel class of vacuum metrics expressible in analytical form was recently found for pure $\mathcal R^2$ gravity, based on a groundwork put forth by Buchdahl in 1962. These Buchdahl-inspired solutions offer a practical framework for testing ${\cal R}^2$ gravity through empirical observations. Within a subclass of asymptotically flat Buchdahl-inspired vacuum spacetimes, we identified a parameter $ε$ measuring the deviation from the classic Schwarzschild metric, which corresponds to $ε=0$. In this paper, we employ observational data from the S2 star's orbit around Sgr A* in the Milky Way galactic center and perform Monte Carlo Markov Chain simulations to probe the effects of the new metrics on the orbit of the S2 star. Our analysis presented herein reports a range at 95\% confidence level on the deviation parameter as $ε\in(-0.6690,\ 0.4452)$. While no decisive evidence either in favor or in disfavor of the asymptotically flat Buchdahl-inspired spacetimes has been achieved, the obtained bound is compatible with the tighter results using other data of different nature as recently reported in Eur.\,Phys.\,J.\,C $\bf 84$, 330 (2024). As a meaningful test probing into a strong-field regime, our present study calls for further observations with prolonged period and improved accuracy in order to tighten the bound for $ε$ using the S2 star orbit.
title Observational test of ${\cal R}^{2}$ spacetimes with the S2 star in the Milky Way galactic center
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2405.10559