Speaker
Description
The study of black hole perturbations typically follows two main approaches: the direct metric perturbation and perturbation via the Newman-Penrose (NP) or Geroch-Held-Penrose (GHP) formalism. In the latter case, a reconstruction method is required, such as the Debye (or Hertz) potential method, to obtain the corresponding metric perturbation. However, the reconstructed metric is expressed in the radiation gauge, which is not always optimal. In this paper, we analyze stationary and axially symmetric perturbations of the Kerr black hole within both frameworks and derive an explicit gauge transformation between the radiation gauges and the standard Weyl-Lewis-Papapetrou (WLP) form of the metric. Additionally, we express the linearised metric coefficients of the WLP metric directly in terms of the Debye potential.
