Identifying modified theories of gravity using binary black-hole ringdowns

Black-hole spectroscopy, that is, measuring the characteristic frequencies and damping times of different modes in a black-hole ringdown, is powerful probe for testing deviations from general theory relativity (GR). In this work, we present comprehensive study on its ability to identify spectrum Kerr black hole GR. Specifically, investigate performance spectroscopy diverse set theoretically motivated as well phenomenologically modified spectra. We find while signal-to-noise ratio ${\ensuremath{\rho}}_{\mathrm{RD}}$ ringdown required modification GR depends details modifications, introduces $\ensuremath{\sim}1%$ shift fundamental mode can typically be distinguished with ${\ensuremath{\rho}}_{\mathrm{RD}}\ensuremath{\in}[150,500]$. This range feasible next-generation detectors, showing promising science case spectroscopy.