arXiv subjects

Ruo-Ting Chen

Publications and source records attributed to Ruo-Ting Chen.

4 recordsLinked to original sources

arXiv2026

Chaos as a Possible Probe for Scalar Hair in Horndeski Gravity

The detection of black hole scalar hair, a possible deviation from general relativity's "no-hair" theorem, requires sensitive probes beyond conventional methods. This study proposes chaotic dynamics as a novel indicator for scalar hair in Horndeski gravity. We investigate the motion of a spinning test particle in a static, spherically symmetric hairy black hole spacetime. Our results show that increasing scalar hair systematically suppresses orbital chaos, as evidenced by regularized precession, reduced Lyapunov exponents, and contracted Poincare sections. Furthermore, scalar hair enhances the correlation between the two gravitational wave polarization modes, restoring phase coherence. These findings demonstrate that chaotic observables and gravitational wave signatures can jointly serve as sensitive probes for black hole hair, offering a complementary approach to testing gravity in strong-field regimes.

gr-qc↗

arXiv2026

Imprints of quantum gravity effects on gravitational waves: a comparative study using extreme mass-ratio inspirals

Within a generally covariant Hamiltonian framework of loop quantum gravity (LQG), two black hole models parameterized by a quantum correction $\zeta$ have recently been constructed. Using extreme mass-ratio inspirals (EMRIs) as high-precision probes, we investigate the imprints of this LQG deformation in the surrounding spacetime. Waveforms generated via an improved augmented analytic kludge (AAK) model in both LQG black hole backgrounds and in Schwarzschild spacetime are compared through a faithfulness analysis. This allows us to quantify the detectability of the deviation with LISA and to derive constraints on $\zeta$ based on a detection threshold. We find that the first LQG black hole model produces significantly stronger signatures in EMRI signals than the second, making its quantum gravity effects more accessible to future space-borne gravitational-wave detection.

gr-qc↗

arXiv2025

Probing loop quantum effects through solar system experiments: observational signatures and parameter constraints

This study investigates quantum gravity effects within the framework of an effective loop quantum gravity (LQG) black hole model parameterized by $\zeta$, utilizing precision measurements from solar system experiments and astrophysical observations. We analyze three classical tests of general relativity (GR): (1) Light deflection constrained by very long baseline interferometry (VLBI) observations of quasar radio signals, (2) Shapiro time delay measurements from the Cassini mission, and (3) Mercury's perihelion precession determined by MESSENGER mission data. Additionally, we extend our analysis to Earth-orbiting LAGEOS satellites and the relativistic trajectory of the S2 star orbiting the Galactic Center supermassive black hole Sagittarius $\rm{A}^*$ (Sgr $\rm{A}^{*}$). Our multi-probe approach reveals that the tightest constraint on the LQG parameter comes from Mercury's perihelion precession, yielding an upper bound $\zeta \lesssim 10^{-2}$. These results establish new observational benchmarks for probing quantum gravity effects.

gr-qc↗

arXiv2024

Constraints from Solar System tests on a covariant loop quantum black hole

Recently, a covariant spherically symmetric model of a black hole within the framework of loop quantum gravity (LQG), characterized by a quantum parameter $r_0$ or $λ$, has been proposed. To derive constraints on the LQG-corrected parameter, we explore observational constraints imposed on $r_0$ and $λ$ through investigations of the light deflection, the Shapiro time delay, the precession of perihelia, and the geodetic precession test. Among these constraints, the tightest one arises from the Shapiro time delay measured by the Cassini mission, yielding an upper constraint of approximately $10^{-5}$.

gr-qc↗