Statistical-thermodynamical foundations of anomalous diffusion

It is shown that Tsallis' generalized statistics provides a natural frame for the statistical-thermodynamical description of anomalous diffusion. Within this generalized theory, a maximum-entropy formalism makes it possible to derive a mathematical formulation for the mechanisms that underly Levy-like superdiffusion, and for solving the nonlinear Fokker-Planck equation.Comment: 13 pages, 8 figures; to appear in special issue of Braz. J. Phys. as invited revie

Complex spatial organization in a simple model of resource allocation

A dynamical model for the distribution of resources between competing agents is studied. While global competition leads to the accumulation of all the resources by a single agent, local competition allows for a wider resource distribution. Multiplicative processes give rise to almost-ordered spatial structures, thourgh the enhancement of random fluctuations.Comment: 4 pages, 3 figures, preliminary versio