Axial gravitational quasinormal modes of magnetically charged black holes*

Abstract In this study, we consider axial perturbations on the magnetically charged string-inspired Euler-Heisenberg black hole. As axial metric perturbation decouples from axial electromagnetic perturbation, we mainly focus on axial gravitational perturbation. By using the Wentzel–Kramers–Brillouin (WKB) approximation and asymptotic iteration method (AIM), we perform a detailed analysis of the gravitational quasinormal frequencies by varying the characteristic parameters of gravitational perturbation and black holes. The results obtained through the AIM are consistent with those obtained using the WKB method, including the results extracted from the time-domain profiles. The greybody factor is calculated using the WKB method. The effects of , ϵ , and multipole number l on the greybody factor are also studied.