Prof. Sharofiddin Urinbaev

This work investigates circular geodesics, orbital dynamics, and radial epicyclic oscillation frequencies of test particles around a static spherically symmetric Kalb-Ramond black hole surrounded by a dark-energy-like anisotropic fluid configuration (ω = −1/2). We map the existence of event horizons in the (l, K) parameter space, establishing upper threshold boundaries: for l = 0, the maximum fluid parameter for horizon existence is Kmax ≈ 0.12, whereas for l = 0.75, Kmax reaches 1.0. Across the physical black hole domain (K ≤ 0.12), we demonstrate that increasing Lorentz violation (l > 0) and adopting more negative fluid intensities (K < 0) significantly deepen the effective potential well. Consequently, the maximum radial epicyclic frequency shifts from the Schwarzschild baseline (Ωr, max ≈ 0.0218 at r ≈ 8.0 M) upward to Ωr, max ≈ 0.1436 at r ≈ 7.2 M for K = −0.1, l = 0.05. Within the Relativistic Precession Model (RPM), these frequency enhancements predict systematic upward displacements in twin-peak quasi-periodic oscillation (QPO) frequencies. Furthermore, comparing our theoretical shadow boundary limits and fundamental oscillation bounds against Event Horizon Telescope (EHT M87*, Sgr A*) angular diameter observations and LIGO/Virgo gravitational-wave ringdown frequencies allows us to establish strong observational constraints on Lorentz-violating antisymmetric tensor fields.