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arXiv · 2604.00570

Probing Lorentz-violating effects via precession and accretion disk images in a rotating bumblebee spacetime

Qing Ou·Zhen-Bo Wu·Qian Wan·Peng-Cheng Li
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Abstract

We investigate kinematic and optical signatures of Lorentz violation in the strong-field region of a rotating bumblebee spacetime generated by a scalar-gradient bumblebee field. For generic nonextremal rotating configurations with $al\neq0$, the surface $r=r_+$ is curvature singular and is therefore modeled phenomenologically as a perfectly absorbing inner boundary in the ray-tracing calculation. By analyzing the spin precession of test gyroscopes and equatorial timelike geodesics, we find that Lorentz violation suppresses the Lense--Thirring precession of static observers, enhances geodetic precession in the static, spherically symmetric limit, and increases the periastron-precession frequency of bound circular orbits. Images of a geometrically thin accretion disk further show that the Lorentz violation has a negligible impact on the critical curve, while shrinking the inner-shadow-like feature associated with the absorbing boundary and enhancing the lensed ring. These results suggest that selected precession observables and exterior imaging features may provide complementary diagnostics of Lorentz-violating effects in strong-field gravity, whereas the central dark feature remains dependent on the adopted inner-boundary prescription.

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Qing Ou, Zhen-Bo Wu, Qian Wan, Peng-Cheng Li. 2026-04-01. Probing Lorentz-violating effects via precession and accretion disk images in a rotating bumblebee spacetime. https://doi.org/10.1088/1475-7516%2F2026%2F08%2F080

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