Optical properties and observational constraints of static neutral black holes in Kalb–Ramond gravity

In Kalb–Ramond gravity, we examine the light rings and shadows of a mono-parametric static neutral Black Hole (BH). The ray-tracing approach is employed to investigate the impact parameter regions associated with direct, lensed and photon ring emissions. We find that each of these areas expands to accommodate solutions for black bouncing. This allows us to ascertain how black bounces appear optically when exposed to three prevalent models of optically and geometrically thin accretion disks in a direct-facing position. We investigate the manifestation, visual characteristics and significance of luminous phenomena, encompassing shadow formation, optical attributes and the explication of luminance variations. Next, we utilize data from the Event Horizon Telescope (EHT) collaboration on M87* and Sgr A* to examine the BH shadows, and efforts have been made to constrain with Lorentz-violating parameter. Furthermore, this study looks into the link between BH shadows and Quasi-Normal Modes (QNMs) for the null geodesic in the eikonal limit. The way BH behaves dynamically is described by the real and imaginary parts of QNM frequencies, which depend on the angular velocity and the Lyapunov exponent. © 2025 Elsevier B.V., All rights reserved.