  Changing-look active galactic nuclei (CL-AGNs) challenges the standard
accretion theory owing to its rapid variability. Recent numerical simulations
have shown that, for the sub-Eddington accretion case, the disk is magnetic
pressure-dominated, thermally stable, and geometrically thicker than the
standard disk. In addition, outflows were found in the simulations.
Observationally, high blueshifted velocities absorption lines indicate that
outflows exist in AGNs. In this work, based on the simulation results, we
investigate the magnetic pressure-dominated disk, and find that the accretion
timescale is significantly shorter than that of the standard thin disk.
However, such a timescale is still longer than that of the CL-AGNs. Moreover,
if the role of outflows is taken into account, then the accretion timescale can
be even shortened. By the detailed comparison of the theoretical accretion
timescale with the observations, we propose that the magnetic
pressure-dominated disk incorporating outflows can be responsible for the rapid
variability of CL-AGNs.
