Quasinormal modes as a distinguisher between general relativity and f(R)
  gravity: Charged black-holes
  The ring-down phase of black-hole perturbations is governed by the
Quasi-Normal modes (QNM) and offer valuable insight into the nature of the
objects emitting them. In General relativity, we identify a dimensionless
parameter that can estimate the charge of a black-hole from the energetics of
quasi-normal modes. We then extend the analysis for f(R) theories of gravity.
Using Isaacson's prescription to modified theories of gravity, we obtain an
accurate and robust method to estimate the difference in the radiated energies
in the scalar and vector modes due to modifications to general relativity. We
then discuss how to quantify the deviation from general relativity.
