Toward a unified view of agnostic parametrizations for deformed black holes
Phys. Rev. D 113, 064010 – Published 3 March, 2026
DOI: https://doi.org/10.1103/x9fw-lrv7
Abstract
A variety of robust and effective descriptions have been devised to extract model-independent information about the fundamental properties of black holes from observational data when searching for deviations from general relativity. In this work, we construct explicit transformation maps establishing the equivalence among three relevant parametrizations for different static and spherically symmetric spacetime patches: the Johannsen-Psaltis parametrization, the Rezzolla-Zhidenko parametrization, and the effective metric description. We then select representative static and spherically symmetric black hole geometries to determine the minimal number of parameters required within each scheme to reproduce the associated quasinormal mode spectra with a prescribed degree of accuracy. Our analysis shows that, for the given observables, a finite set of coefficients suffices to attain the desired precision in the three frameworks. Finally, we emphasize how the individual strengths of these effective descriptions can be exploited to probe complementary aspects of black hole physics.
