Warping of accretion disks with magnetically driven outflows: A possible origin for jet precession

Current theoretical models for the outflows/ jets from active galactic nuclei, X-ray binaries, and young stellar objects involve large-scale magnetic fields threading an underlying accretion disk. We suggest that such a disk is subjected to warping instability and retrograde precession driven by magnetic torques associated with the outflow. The growth timescale for the disk warp and the precession period are of order the radial infall time of the disk. These effects may be relevant to jet precession and other variabilities observed in many systems.