Charged Black Holes: Wave Equations for Gravitational and Electromagnetic Perturbations

A pair of wave equations for the electromagnetic and gravitationalperturbations of the charged Kerr black hole are derived. The perturbedEinstein-Maxwell equations in a new gauge are employed in the derivation. Thewave equations refer to the perturbed Maxwell spinor $\Phi_0$ and to the shear$\sigma$ of a principal null direction of the Weyl curvature. The wholeconstruction rests on the tripod of three distinct derivatives of the firstcurvature $\kappa$ of a principal null direction.Comment: 12 pages, to appear in Ap.