  We perform magnetohydrodynamic simulations of accreting, equal-mass binary
black holes in full general relativity focusing on the effect of spin and
minidisks on the accretion rate and Poynting luminosity variability. We report
on the structure of the minidisks and periodicities in the mass of the
minidisks, mass accretion rates, and Poynting luminosity. The accretion rate
exhibits a quasi-periodic behavior related to the orbital frequency of the
binary in all systems that we study, but the amplitude of this modulation is
dependent on the existence of persistent minidisks. In particular, systems that
are found to produce persistent minidisks have a much weaker modulation of the
mass accretion rate, indicating that minidisks can increase the inflow time of
matter onto the black holes, and dampen out the quasi-periodic behavior. This
finding has potential consequences for binaries at greater separations where
minidisks can be much larger and may dampen out the periodicities
significantly.
