Quasinormal modes, shadow, and greybody factors of 5D electrically charged Bardeen black holes

We study quasinormal modes (QNMs) in a five-dimensional electrically charged Bardeen black hole spacetime by considering the scalar and electromagnetic field perturbations. The black hole spacetime is an exact solution of Einstein gravity coupled to nonlinear electrodynamics in five dimensions, which has nonsingular behavior. To calculate QNMs, we use the WKB approximation method up to sixth order. Due to the presence of electric charge ${q}_{e}>0$, both the scalar and electromagnetic field perturbations decay more slowly when compared to the Schwarzschild-Tangherlini black holes. We discover that the scalar field perturbations oscillate more rapidly compared to the electromagnetic field perturbations. In terms of damping, the scalar field perturbations damp more rapidly. We graphically show that the transmission (reflection) coefficients decrease (increase) with an increase in the magnitude of the electric charge ${q}_{e}$. The emission of gravitational waves allows the spacetime to undergo damped oscillations due to the nonzero value of the imaginary part, which is always negative. The imaginary part of the QNM frequencies continuously decreases with an increase in the magnitude of the electric charge ${q}_{e}$ for a given mode ($l$, $n$). A connection between the QNM frequencies and the black hole shadow, as well as the geometric cross section in the eikonal limit, is also described.

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