Gravitational quasinormal modes of a parametrized Schwarzschild metric

Recently, a parametrized Schwarzschild metric (PSM) was proposed, in which n = 2 to solve the differences of mass of M87* from different observations. We find the axial gravitational quasinormal modes of this metric are unstable for n > 1. The decay rate of the quasinormal mode of the case n < 1 is much smaller than the case n = 1, which can be used to differentiate the PSM from a Schwarzschild one.

Automated summary

A parametrized Schwarzschild metric (PSM) has been proposed recently to address the differences in mass of M87* from different observations. It was found that the axial gravitational quasinormal modes of this metric are unstable for n > 1. The decay rate of the quasinormal mode is much smaller for n < 1, which can be used to distinguish the PSM from a Schwarzschild metric.