Lorentz corrections in electrical conductivity

In a medium consisting of a spatially uniform source of scattering supplemented by randomly distributed localized scatterers, the current distribution is spatially nonuniform. The nonuniformity arises from the fact that the current flow suffers a detour near an obstacle to the extent that the localized scatterer's cross section exceeds that of the equivalent volume of background material. Thus a typical obstacle will be exposed to an incident current which has been increased by the "detour" currents of the other scatterers. This increase in the local current incident on an obstacle results in a contribution to resistivity which is nonlinear in both the density of the obstacles and in their scattering cross sections. © 1972 by The American Physical Society.