The Thematic Institute (TI) - together with the two accompanying Topical Workshops (TW I / II) - is part of the activities of the European Network of Excellence (NoE) ``Complex Systems'' (EXYSTENCE). It takes place at the Max-Planck Insitute for Physics of Complex Systems (MPIPKS) in Dresden from Monday, 19 July 2004, to Friday, 17 September 2004, and is jointly financed by EXYSTENCE and the MPIPKS.

EXYSTENCE is founded by the European Commission within the Future Emerging Technologies (FET) Programme of the Information Society Technologies (IST) Programme of the Fifth Framework (IST-2001-32802) from March 2002 until September 2005. The NoE aims to develop collaboration among European researchers interested in Complex Systems, from fundamental concepts to applications, and involving academia, business and industry.

TI/TW of the NoE have to focus on issues of Complex Systems from a broader perspective. They should cover transdisciplinary aspects of Complex Systems, in order to develop a commonality of concepts and methods applicable to different fields.

The TI ``From Many-Particle Physics to Multi-Agent Systems'' matches these conditions in various respects. It aims at a transfer of methods developed primarily in statistical physics to deal with many-particle systems in other scientific areas, such as biology, artificial intelligence, or social sciences. Certainly, the basic entities in these fields differ from physical ``particles'' in that they already have an intermediate complexity themselves. Therefore, these entities today are commonly denoted as agents. This term means a subunit of the system that may already have internal degrees of freedom to allow certain activities, such as (active) movement, and interaction with other agents.

Systems comprised of a (usually large) number of (usually strongly) interacting agents (entities, components, ...) are denoted as Complex Systems, because the system behavior cannot be simply inferred from the behavior of the components. That is, self-organization and emergent properties play an important role in determining the resulting spatio-temporal patterns, or the collective ``behavior'' on the macroscopic level.

In order to gain insight into the interplay between microscopic interactions and macroscopic features in complex systems, it is important to find a modeling level, which on one hand considers specific features of the system and is suitable to reflect the origination of new qualities, but on the other hand is not flooded with microscopic details. In this respect microscopic, i.e. particle-based and agent-based models have become a very promising approach to investigate and to simulate complex systems. A commonly accepted theory of multi-agent systems that also allows analytical investigations is however still pending. It will be a multi-disciplinary challenge to improve this situation, in which also statistical physics needs to play its part, both by contributing concepts and formal methods. Its long lasting experience in describing many-particle systems, to deduce the structure, properties and dynamics of matter from microscopic interaction laws, may serve as a paragon also for other scientific areas, where one would finally like to explain the observed macroscopic dynamics based on non-linear interactions among a large number of different agents.

The TI/TW want to contribute to this development, by bringing together scientists from different fields who deal with many-particle and multi-agent systems, to allow mutual interaction and new insights - both for physicists who want to apply their methods to interdisciplinary problems, and for scientists from other fields interested in formal methods developed for interacting particle systems.