Published online by Cambridge University Press: 13 March 2009
A closed solution for the increment in the logarithmic derivative &dgr;(Q) over the inner (‘resistivity’) region for resistive tearing theory in cylindrical geometry including ‘parallel’ viscosity is compared with an earlier numerical solution. The singular point Qcrit about which δ(Q) exhibits branch-point behaviour in the presence of compressibility is identified; modification of the viscous theory, to include (for example) finite Larmor radius effects, is suggested. In the incompressible limit, a familiar (inviscid) stability criterion is recovered, in the presence of ‘parallel’ viscosity.