Note on the parametrized black hole quasinormal ringdown formalism

Understand

The parametrized black hole quasinormal ringdown formalism is useful to compute quasinormal mode (QNM) frequencies if a master equation for the gravitational perturbation around a black hole has a small deviation from the Regge-Wheeler or Zerilli equation.

• In this formalism, the deviation of QNM frequency from general relativity can be calculated by small deviation parameters and model independent coefficients.
• In this paper, we derive recursion relations for the model independent coefficients.
• Using these relations, the higher order coefficients are written only by the lower order coefficients.