The relation between diffusion and conductivity is established for a case of diffusing particle moved by means of Levy hops. It is shown that due to an unusual character of the Levy flight a particle velocity depends on electrical field in nonlinear way in arbitrary weak fields. A nonlinear...

The random walks on the comb structure are considered. It is shown that due to fingers a diffusion has an anomalous character, that is an r.m.s. displacement depends on time by a power way with exponent 12. The generalized diffusion equation for an anomalous case is deduced. It essentially...