Extracting linear and nonlinear quasinormal modes from black hole merger simulations

• DOI: 10.48550/arxiv.2310.04489
• Publication Date: 2023-01-01
• Authors: Mark Ho-Yeuk Cheung; Emanuele Berti; Vishal Baibhav; R. Cotesta
• Keywords: Black hole (networking); Quasinormal mode; Mass ratio

In general relativity, when two black holes merge they produce a rotating (Kerr) hole remnant. According to perturbation theory, the remnant emits "ringdown" radiation: superposition of exponentials with characteristic complex frequencies that depend only on remnant's mass and spin. While goal spectroscopy program is measure quasinormal mode frequencies, knowledge their amplitudes phases equally important determine which modes are detectable, possibly perform additional consistency checks. Unlike properties binary progenitors, such as ratio component spins. this paper we develop fitting algorithm designed reliably identify present in numerical simulations extract phases. We apply over 500 from public SXS relativity simulation catalog, formulas for resulting functions progenitors. Crucially, our allows extraction not prograde fundamental overtones, but also retrograde second-order modes. unveil interesting relations amplitude ratios different The code interactive versions some plots publicly available. results presented can be updated more better become