Model-independent Search for the Quasinormal Modes of Gravitational Wave Echoes

Postmerger gravitational wave echoes provide a unique opportunity to probe the near-horizon structure of astrophysical black holes, which may be modified due to nonperturbative quantum gravity phenomena. However, since the waveform is subject to large theoretical uncertainties, it is necessary to develop search methods that are less reliant on specific models for detecting echoes from observational data. A promising strategy is to identify the characteristic quasinormal modes (QNMs) associated with echoes, in frequency space, which complements existing searches of quasiperiodic pulses in time. In this talk, I'll introduce the Bayesian search algorithm we've recently developed to detect these long-lived QNMs using phase-marginalized likelihood functions. The algorithm has been validated with signal injections in Gaussian noise for complementary echo waveforms. To work with real data, we've also accounted for the effects of non-Gaussian artifacts. We've conducted some of the proposed searches on real data from the first observing run of Advanced LIGO.

Note this seminar will take place only on Zoom;