Probing Observable Features of Lorentz violation in Low-Energy Ho\v{r}ava Gravity with Accretion Disk Images of Black Hole

TL;DR

This study investigates how Lorentz violation in low-energy Horava gravity influences black hole images and polarization, proposing observational tests with future high-resolution telescopes.

Contribution

It numerically simulates observable signatures of Lorentz violation in rotating black holes, linking LV parameters to image and polarization features.

Findings

LV parameter l significantly affects black hole shadow shape and polarization.

Increasing l produces a D-shaped critical curve, decreasing l results in an elliptical shadow.

Sign of l influences black hole angular velocity and LV effect trends.

Abstract

In this paper, we study the observable signatures of Lorentz violation (LV) in low-energy Horava gravity by simulating the images and polarization features of rotating LV black holes using a backward ray-tracing method. Within a thin-disk accretion model and the ZAMO framework, we numerically solve the geodesics equation of photon and simulate the corresponding thin-disk images and polarization patterns. The results show that the LV parameter l strongly affects the inner shadow, brightness asymmetry, and polarization properties of the thin disk. The decrease of l leads to a more elliptical and untilted inner shadow, while increasing l produces a pronounced leftward D-shaped structure of the critical curve. In addition, the variation of l alters the distribution of polarized intensity and polarization direction, especially near the critical curve. Moreover, it also shows that a positive l enhances the black hole's angular velocity, while a negative one suppresses it, indicating that the sign of l determines the trend direction of the LV effect. These findings suggest that future high-resolution EHT observations combining the thin-disk images and polarization patterns could provide valuable tests of the LV effect.