Purpose of Many-Body Systems Science Unit

A material consisting of an enormous number of atoms, a living organism consisting of a large number of cells, a society consisting of a large number of humans, or an ecosystem consisting of a large number and variety of organisms are interacting many-body systems consisting of a large number of elements. In other words, energy and materials are exchanged between elements and information is exchanged between individuals while each element and individual is in various states. Such systems are referred to as 'complex systems'. Complex systems often show co-operative phenomena and co-ordinated movements that cannot simply be predicted from the laws of the individuals. Phase transitions from liquids to solids and the transition of smoothly flowing traffic flows into traffic jams are examples of such cooperative phenomena.

To understand such phenomena, traditional analytical research methods are not sufficient; an integrated way of thinking is required. In addition, it is nowadays necessary to incorporate not only classical mechanics but also quantum mechanics as the fundamental laws of individual elements.

In this course, the principles for understanding complex system phenomena in a unified manner will be investigated by developing and utilising the thinking tools of both elemental reduction and holistic integration based on the concepts and methods of statistical mechanics developed in physics and the latest perspectives and methods of information science. Research and education is also conducted to utilise the methodologies and findings obtained in this way for clarifying and solving problems in nature and society at large.