Binary Black Hole mergers and galaxies' central black holes

The origin of the binary black hole (BBH) mergers that LIGO/Virgo have detected is unclear, and it is likely that multiple formation mechanisms are at play. In this talk, I will present a new formation channel for LIGO/Virgo BBHs, which places such black holes at the center of very low mass dwarf galaxies. Another interesting possibility is that stellar mass BBHs merge around more massive central black holes, in Active Galactic Nuclei (AGN) disks. I will mention how both of these scenarios are relevant for to the most massive binary black hole merger detected to date, GW190521, and how confident associations and cosmological contraints can be placed with future gravitational wave detections and AGN catalogs or follow-up observations.