Probing Lorentz-violating effects via precession and accretion disk images of a rotating bumblebee black hole

TL;DR

This paper explores how Lorentz-violation affects black hole signatures, including precession behaviors and accretion disk images, potentially aiding in testing fundamental physics in strong gravity regimes.

Contribution

It provides the first detailed analysis of Lorentz-violating effects on black hole precession and accretion disk images, highlighting observable signatures for future tests.

Findings

Lorentz-violation suppresses Lense-Thirring precession near the horizon.

It enhances geodetic precession in the spherically symmetric limit.

Inner shadow size decreases significantly due to Lorentz-violation.

Abstract

We investigate kinematic and optical signatures of Lorentz-violation in the strong-field region of a rotating bumblebee black hole generated by a scalar-gradient bumblebee field. Through the analysis of spin precession of test gyroscopes and timelike geodesic motion in the spacetime, we find that Lorentz-violating effect suppresses the Lense-Thirring precession near the horizon, while enhancing geodetic precession in the static, spherically symmetric limit. For bound circular orbits in the equatorial plane, the Lorentz-violation leads to an increase in the periastron precession frequency. Furthermore, images of a geometrically thin accretion disk reveal that the Lorentz-violation has a negligible impact on the critical curve, but significantly shrinks the inner shadow and enhances the lensed ring. These results indicate that inner shadow measurements, combined with selected precession observables, may provide complementary probes of Lorentz-violating effects in strong-field gravity.