Binary black hole mergers in AGN accretion discs: gravitational wave rate density estimates

Understand

The majority of gravitational wave (GW) events detected so far by LIGO/Virgo originate from binary black hole (BBH) mergers.

• Among the different binary evolution paths, the merger of BBHs in accretion discs of active galactic nuclei (AGNs) is a possible source of GW detections.
• We consider an idealised analytical model of the orbital evolution of BBHs embedded in an AGN accretion disc.
• In this framework, the disc-binary interaction increases the orbital eccentricity and decreases the orbital separation, driving the BBH into a regime where GW emission eventually leads to coalescence.