Observational Constraints on f(R,T) gravity coupled with NED from Black Hole Quasi Periodic Oscillations

Abstract: In this work, we examine the influence of nonlinear electrodynamics (NED) and $f(R,T)$ gravity on quasi-periodic oscillations (QPOs) around a magnetically charged black hole. By analyzing the effective potential, specific energy, and angular momentum of circular orbits, we study how the NED parameter $\alpha$ and the gravitational coupling parameter $\beta$ affect orbital dynamics. Increasing $\alpha$ leads to systematic deviations from the Reissner Nordstrom behavior, reflected in shifts in the ISCO radius and orbital frequencies. We further explore QPO-generating radii using the Relativistic Precession (RP), Warped Disk (WD), and Epicyclic Resonance (ER2-ER4) models. We further extend our analysis by performing an MCMC-based parameter estimation using QPO data from black holes spanning a wide range of mass scales. This approach yields consistent observational constraints on the model parameters.