Self-Organized Criticality

Abstract

The study of out-of-equilibrium dynamics (e.g. dynamical phase transitions) and of heterogeneous systems (e.g. spin-glasses) has progressively made popular the concept of complex systems and the importance of systemic approaches: systems with a large number of mutually interacting parts, exchanging energy, matter or information with their environment, self-organize their internal structure and their dynamics with novel and sometimes surprising macroscopic (“emergent”) properties. The complex system approach, which involves “seeing” inter-connections and relationships i.e. the whole picture as well as the component parts, is nowadays pervasive in modern control of engineering devices and business management. It also plays an increasing role in most of the scientific disciplines, including biology (biological networks, ecology, evolution, origin of life, immunology, neurobiology, molecular biology, etc), geology (plate-tectonics, earthquakes and volcanoes, erosion and landscapes, climate and weather, environment, etc.), economy and social sciences (including cognition, distributed learning, interacting agents, etc.).