Bayesian analysis of analog gravity systems with the Rezzolla-Zhidenko metric

Analog gravity systems have the unique opportunity to probe theoretical aspects of black hole physics in a controlled laboratory environment that one cannot easily observe for astrophysical black holes. In this work, we address the question of whether one could use controlled initial perturbations to excite the black hole ringdown and infer the effective black hole metric. Using a theory-agnostic ansatz for the effective metric described by the Rezzolla-Zhidenko metric and evolving perturbations on that background, we quantify with Bayesian analysis what regions of the effective spacetime could be constrained in experiments. In contrast to standard ringdown analyses based on quasi-normal mode extraction, a laboratory-controlled setup, in combination with our framework, allows one to model the entire signal, including the prompt response and possible effects of late-time tails. Therefore, it has the intriguing advantage of not relying on start and end times when the superposition of quasi-normal modes is a good signal approximation. It also avoids the non-trivial question of how many modes are present. We demonstrate that this approach is feasible in principle and discuss opportunities beyond this study.