Photonsphere, shadow, quasinormal modes, and greybody bounds of non-rotating Simpson-Visser black hole (2309.06454v1)

Abstract: In this manuscript, we study photonsphere, shadow, quasinormal modes, Hawking temperature, and greybody bounds of a non-rotating Simpson-Visser black hole which is a regular black hole. We observe that though the radius of the photonsphere does depend on the Simpson-Visser parameter $\alpha$, the shadow radius is independent of it. The shadow radius is found to be equal to that for Schwarzschild black hole. We, then, study quasinormal frequencies of the Simpson-Visser black hole for scalar and electromagnetic perturbations with the help of $6$th order WKB method. We tabulate values of quasinormal frequencies for various values of $\alpha$, angular momentum $\ell$, and overtone number $n$. We also graphically show the dependence of real and imaginary parts of quasinormal frequency on $\alpha$ and $\ell$. Additionally, We study the convergence of the WKB method for various values of pair $(n,\ell)$. Finally, we shed light on the dependence of the Hawking temperature on the parameter $\alpha$ and the dependence of greybody bounds on $\alpha$ and $\ell$.