Helicity fluctuation, generation of linking number and effect on resistivity

Abstract

The energy of the stochastic magnetic field is bounded from below by a topological quantity expressing the degree of linkage of the field lines. When the bound is saturated one can assume that the storage of a certain magnetic energy requires a minimal degree of topological complexity. It is then possible to infer a connection between the helicity content and the average curvature of the magnetic field lines. The random curvature induce random drifts leading to an additional dissipation and modified resistivity.