Title:STRANGE DIFFUSION
Authors:R.Balescu (Association Euratom - Etat Belge pour la Fusion, Universit\'{e} Libre de Bruxelles, CP 231, Campus Plaine, Bd. du Triomphe, 1050 Bruxelles, Belgium)

Strange diffusion is defined as a process in which the mean square displacement of a randomly walking test particle behaves asymptotically as $\boldsymbol{\left\langle x^{2}(t)\right\rangle{\sim}\:t^{\alpha}}$, with $\boldsymbol{\alpha{\neq}1}$. A brief review of the properties of such processes is presented, stressing their deep difference from the corresponding normal diffusive evolution. A number of examples are discussed, including diffusion of charged particles in a fluctuating magnetic field, continuous time random walks and transport in chaotic Hamiltonian systems.

Key words: strange diffusion, random process, chaos
Comments: Figs. 8, Refs. 29, Tabs. 0.