This concept is not totally new. However, the currently accepted criterion for stability is that the toroidal magnetic field cannot be significantly larger than the poloidal field. The extent of the magnetosphere is determined by the condition at its edge and therefore must depend on the resistivity of the disc, given the assumption of quasi-steady state. If the resistivity has two values, the stable outer magnetosphere must have two states. As the outer magnetosphere is bounded at the corotation radius, where the toroidal field is zero, one would expect that any variation in the outer magnetosphere will stop at the corotation radius.
Problems exist for the nature of the viscosity in the presence of strong magnetic field.
Assuming a normal disc when no stellar magnetic connection is present, the presence of star-disc magnetic interaction must alter the nature of the viscosity. The situation is just opposite outside the corotation radius, as the magnetospheric interaction tends to spin up the disc and so the viscosity must be larger enough to carry away more angular momentum. In this sense, the stellar magnetic connection adds a component to the normal viscosity in a normal disc. By the argument above for the outer magnetosphere, we have to conclude that the part associated with magnetospheric interaction opposes the normal part. The conductivity relates to the normal viscosity part , which depends on the strength of the turbulence.