The Acceleration of the Gravitational Wave Events Through the Circumbinary Disk Around Two Inspiraling Black Holes

Abstract

Abstract The observation of gravitational wave opens a new window for both physics and astrophysics. Among the models of the formation of binary black holes (BHs), some suggest the existence of circumbinary disk, which may provide the material to ignite the electromagnetic radiation observable to modern astronomical facilities. In this work, we investigate the consequences of such circumbinary disk, with an emphasis on the reduction in the BH-BH merger timescale, i.e. the total time necessary for the gravitational wave events to happen. We find that, the circumbinary disk excites a tidal torque onto the BH-BH system, and it dominates the angular momentum transfer (outward) when the BH-BH separation a> xxx. Theoretical implications of this result are discussed.