Dynamics of Eulerian walkers
  We investigate the dynamics of Eulerian walkers as a model of self-organized criticality. The evolution of the system is subdivided into characteristic periods which can be seen as avalanches. The structure of avalanches is described and the critical exponent in the distribution of first avalanches $\tau=2$ is determined. We also study a mean square displacement of Eulerian walkers and obtain a simple diffusion law in the critical state. The evolution of underlying medium from a random state to the critical one is also described. 
A.M. Povolotsky, V.B. Priezzhev, R.R. Shcherbakov