Speaker
Description
Tidal disruption events (TDEs), apart from producing luminous electromagnetic (EM) flares, can generate potentially detectable gravitational wave (GW) burst signals by future space-borne GW detectors. We propose the first methodology to constrain the Hubble constant $H_0$ with TDEs by incorporating the EM-observable parameters (e.g., stellar mass, black hole (BH) mass, and spin) into fitting the observed TDE GW burst waveforms. We argue that an accurate knowledge of the BH spin could help constrain the orbital inclination angle, hence alleviating the well-known distance-inclination degeneracy in waveform fitting. For individual TDEs, the precise redshift measurement of the host galaxies along with the luminosity distance $D_{\rm L}$ derived from the combination of EM and GW signals would give a self-contained measurement of $H_0$ via Hubble's law, completely independent of any specific cosmological models. As the simultaneous EM-GW detections proliferate, TDE demographic analysis could lead to an accurate measurement in addition to the standard siren approach.
