  Binary systems with comparable masses and a surrounding accretion disk can
accrete gas through spiral accretion streams penetrating the central cavity
formed by tidal interactions. Using three-dimensional Newtonian
magnetohydrodynamics simulations, we investigate the possibility of a
magnetically arrested accretion flow through the cavity. Rather than solely
continuously feeding the binary through spiral accretion streams, the accretion
is regulated by the strong magnetic field inside the cavity. Transport of mass
and angular momentum onto the binary then proceeds largely periodically in
magnetic flux eruption episodes. The ejected flux tubes carry angular momentum
outwards and away from the binary, inject hot plasma into the disk and can
launch flares. This likely intermittent scenario could have potential
implications for the emission signatures of supermassive black hole binaries,
and potentially shed light onto the role magnetic fields play in the binary's
orbital evolution.
