Epicyclic frequencies around charged regular black hole: constraints using different quasars data

Abstract We examine the dynamics of test particles and epicyclic frequencies around a charged regular black hole, investigating how its mass M and charge q influence orbital motion, stability, and high-energy phenomena. Using an effective potential approach, we derive analytical expressions for the specific energy and angular momentum of particles in stable circular orbits, demonstrating that increasing q shifts the innermost stable circular orbits (ISCOs) inward compared to the Schwarzschild black hole. We compute the radial, vertical, and orbital oscillation frequencies, revealing significant deviations from standard black hole predictions, particularly in the 3:2 frequency ratio associated with high-frequency. Through Markov Chain Monte Carlo (MCMC) analysis of observational data from X-ray binaries (including H 1743-322 and GRS 1915+105), we constrain the charge parameter to $$q/M \sim 0.3$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>/</mml:mo> <mml:mi>M</mml:mi> <mml:mo>∼</mml:mo> <mml:mn>0.3</mml:mn> </mml:mrow> </mml:math> –0.4 at high confidence levels. Further, we study particle collisions near the horizon, finding that centre-of-mass energies can be enhanced by up to 40% for $$q \approx 0.6M$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>≈</mml:mo> <mml:mn>0.6</mml:mn> <mml:mi>M</mml:mi> </mml:mrow> </mml:math> , indicating observable signatures in high-energy astrophysical processes. Our results provide testable predictions for distinguishing charged regular black holes from classical singular black holes. This work establishes a framework for probing black hole structures in the strong-gravity regime, with implications for fundamental physics and quantum gravity.