Bounds on Λ at the Galactic Center
Abstract
We constrain the cosmological constant, Λ, using astrometric and spectroscopic observations of the S2 star, supplemented by S1 and S14 stars orbiting Sgr A*. We develop a framework for modelling relativistic stellar orbits in general spherically symmetric spacetimes and perform Bayesian parameter estimation to jointly infer orbital and spacetime parameters. Applying this framework to Schwarzschild-de Sitter spacetime, we obtain upper bounds on Λ. The individual constraints exhibit the expected dependence on the dynamical timescales of the stars, with the longer-period S1 providing the strongest sensitivity. Combining the individual constraints, we obtain Λ≲ 6.9×10−48m−2 at 68\% credibility and Λ≲ 1.0×10−38m−2 at 95\% credibility. The 68\% constraint is the strongest bound at a comparable dynamical timescale.
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BibTeX
@misc{puttasiddappa2026bounds,
title = {{Bounds on $Λ$ at the Galactic Center}},
author = {Prajwal Hassan Puttasiddappa and Muzammil Mushtaq and William Ramirez and David F. Mota},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.13356},
eprint = {2606.13356},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.13356},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Bounds on Λ at the Galactic Center
AU - Prajwal Hassan Puttasiddappa
AU - Muzammil Mushtaq
AU - William Ramirez
AU - David F. Mota
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2606.13356
UR - https://arxiv.org/abs/2606.13356
AB - We constrain the cosmological constant, Λ, using astrometric and spectroscopic observations of the S2 star, supplemented by S1 and S14 stars orbiting Sgr A^*. We develop a framework for modelling relativistic stellar orbits in general spherically symmetric spacetimes and perform Bayesian parameter estimation to jointly infer orbital and spacetime parameters. Applying this framework to Schwarzschild-de Sitter spacetime, we obtain upper bounds on Λ. The individual constraints exhibit the expected dependence on the dynamical timescales of the stars, with the longer-period S1 providing the strongest sensitivity. Combining the individual constraints, we obtain Λ≲ 6.9×10^−48m^−2 at 68\% credibility and Λ≲ 1.0×10^−38m^−2 at 95\% credibility. The 68\% constraint is the strongest bound at a comparable dynamical timescale.
ER -