Inductionless magnetorotational instability beyond the Liu limit

Employing the short wavelength approximation, we develop a unified framework for the investigation of the standard, the helical, and the azimuthal version of the magnetorotational instability (MRI) as well as of the current-driven Tayler instability. We show that the inductionless types of MRI that were previously thought to be restricted to comparably steep rotation profiles extend well to the Keplerian case if only the azimuthal field deviates slightly from its field-free profile.