  We give a pedagogical introduction to black holes (BHs) greybody factors
(GFs) and quasinormal modes (QNMs) and share the recent developments on those
subjects. In this study, our primary focus will be on the bosonic and fermionic
GFs and QNMs of various BH and brane geometries and reveal the fingerprints of
the invisibles with the radiation spectra to be obtained by the WKB
approximation and bounding the Bogoliubov coefficients (together with the
Miller-Good transformation) methods. (*Due to the notification of arXiv "The
Abstract field cannot be longer than 1,920 characters", the appeared Abstract
is shortened. For the full Abstract, please download the Article.)
