  Physicists study a wide variety of phenomena creating new interdisciplinary
research fields by applying theories and methods originally developed in
physics in order to solve problems in economics, social science, biology,
medicine, technology, etc. In their turn, these different branches of science
inspire the invention of new concepts in physics. A basic tool of analysis, in
such a context, is the mathematical theory of complexity concerned with the
study of complex systems including human economies, climate, nervous systems,
cells and living things, including human beings, as well as modern energy or
communication infrastructures which are all networks of some kind. Recently,
complexity has become a natural domain of interest of the real world
socio-cognitive systems, linguistics, and emerging systemics research. The
phenomena to be studied and understood arise from neither the physical laws nor
the abstraction of mathematics. The challenge is to discern and formulate
plausible mathematical structures to describe problems that represent vague
human goals.
