17-06U

The paper is a brief essay about statistical physics of complex systems, the  research direction that now acquires features of the well established field of science with its object of study, conceptual background and methods of analysis. Examples of complex systems are found in condensed matter, ecological and biological systems, human society, stock markets and economy. The concept of a complex system forms a new, inter-disciplinary branch of knowledge. Peculiar features of complex systems are self-organization, emergence of new functionalities, adaptive nature of interactions, high sensitivity to small changes in the initial conditions, governing power laws (“fat-tailed” distributions). Together with general description of the properties of complex systems, we give a brief overview of some studies performed in this field at the Institute for Condensed Matter Physics of the NAS of Ukraine.