Even parity potential for spacetimes with Gaussian matter source and its associated QNM spectra

Abstract

We have obtained the general form of even mode potential function for the gravitational perturbation of a static spherically symmetric spacetime. Considering the minimal-spread Gaussian matter source, parameterized by a smearing length scale {\Theta}, the associated quasinormal mode (QNM) frequencies are computed numerically using the well known WKB formula. A comparative study on the accuracy of the results based on different approximation orders of the WKB formula indicates that the smearing parameter {\Theta} has an upper bound, beyond which the spectra of odd and even modes deviate from their usual isospectral nature.