"Avalanche dynamics on complex networks"
Recently the emergence of a power-law degree distribution in complex networks have attracted considerable attentions. Such scale-free (SF) networks are ubiquitous in nature. Due to the heterogeneity in degree, SF networks are vulnerable to attack on a few nodes with large degree. However, more severe catastrophe can occur, triggered by a small fraction of nodes but causing a cascade of failures of other nodes. The recent blackout of power transportation in the northeastern US and Italy is a typical example of such a cascading failure. Here, to study the avalanche dynamics, we investigate the Bak-Tang-Wiesenfeld sandpile model on SF networks, a prototypical model exhibiting the avalanch dynamics. We obtain the avalanche size distribution analytically by using the branching process approach. Finally, related problems in various systems such as the metabolic networks and the Internet will be discussed.