On tearing modes in a resistive medium

The theory of tearing modes in cylindrical symmetry is reexamined. The resistive medium is characterized by the simplest Ohm's law. By considering β, the ratio of thermal to magnetic pressure, as a parameter with respect to which the sought-after eigenvalues were scaled, a very simple description was obtained. Many of the classical results were obtained in a more simple way. Among the new results are: (1) the possibility of the existence of a tearing mode on a resistive time scale, which is hardly affected by drift effects; and (2) for modes of an almost marginal growth rate inertia does not play an important role, slab and cylindrical modes are fundamentally different, and finite-β effects play a crucial role.