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

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 $al\ne 0$, 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.

Revised version after journal publication, with clarifications concerning the geometrical interpretation of the spacetime and the inner-boundary prescription. The main results and conclusions remain unchanged. Published in JCAP 08 (2026) 080

References in corpus (14)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• Black Hole Shadows, Photon Rings, and Lensing Rings
• Gravitational Test Beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole
• Observing the Inner Shadow of a Black Hole: A Direct View of the Event Horizon
• Black holes with a cosmological constant in bumblebee gravity
• QED Effect on Black Hole Shadow
• Orbital and epicyclic frequencies around rapidly rotating compact stars in scalar-tensor theories of gravity
• Testing EGB gravity coupled to bumblebee field and black hole parameter estimation with EHT observations
• Timelike bound orbits and pericenter precession around black hole with conformally coupled scalar hair
• Dynamic instability analysis for bumblebee black holes: the odd parity
• Kerr-scalaron metric and astronomical consequences near the Galactic Center black hole
• Periodic orbits and gravitational waveforms of black holes in bumblebee gravity