Abstract
We follow the evolution of supermasive black hole (BH) pairs in the last stages of their evolution r ~ pc. We have used a semianalytical model that includes a BHs binary system with triple disks, the mass added to the circumbinary disk due to cosmic accretion and the corresponding exchange of angular momentum between accretion, mass transfer and orbital motion. While the circumbinary disk removes angular momentum, the cosmological mass transfer adds some fraction of its angular momentum to the orbital angular momentum of the BH pair.
