1 2 Jean-Dominique Deuschel and Andreas Greven 1 Fakult] at II - Mathematik und Naturwissenschaften, Institut fur ] Mathematik, Technische Universit] at Berlin, Strasse des 17. Juni 136, D-10623 Berlin Tel. (0049 30) 314-25193, Fax: (0049 30) 314-21695 deuschel@math. tu-berlin. de 2 1 Mathematisches Institut, Bismarckstr. 1, D-91054 Erlangen, 2 Tel. (0049 9131) 85-22454, Fax (0049 9131) 85-26214 This volume collects original work and reviews on work in the ?eld of pro- bilitywhichtookplacewithintheframeworkoftheDFG-Schwerpunkt: Int- acting stochastic systems of high complexity. This research network started in May 1997 and was funded till May 2003. In this network between 20 30 (depending on the 2-year periods of grant renewal) groups from probab- ity, statistical physics and mathematical statistics within Germany were - tive. An extensive international collaboration was an essential part of this network and here particularly intense contacts were built up between the DFG-Schwerpunkt and EURANDOM, a European institute for research in stochastics, which was founded in 1997. This partnership reached from joint workshops and colloquia to collaborations on speci?c projects. The key scienti?c idea which was behind the research network was to - plore and develop the connections between research in in?nite dimensional stochastic analysis, statistical physics (Gibbs measures, random media), s- tial population models from mathematical biology, complex models of ?n- cial markets or of stochastic models with interacting components in other sciences as for example in climatology."

This book constructs a rigorous framework for analysing selected phenomena in evolutionary theory of populations arising due to the combined effects of migration, selection and mutation in a spatial stochastic population model, namely the evolution towards fitter and fitter types through punctuated equilibria. The discussion is based on a number of new methods, in particular multiple scale analysis, nonlinear Markov processes and their entrance laws, atomic measure-valued evolutions and new forms of duality (for state-dependent mutation and multitype selection) which are used to prove ergodic theorems in this context and are applicable for many other questions and renormalization analysis for a variety of phenomena (stasis, punctuated equilibrium, failure of naive branching approximations, biodiversity) which occur due to the combination of rare mutation, mutation, resampling, migration and selection and make it necessary to mathematically bridge the gap (in the limit) between time and space scales.

1 2 Jean-Dominique Deuschel and Andreas Greven 1 Fakult] at II - Mathematik und Naturwissenschaften, Institut fur ] Mathematik, Technische Universit] at Berlin, Strasse des 17. Juni 136, D-10623 Berlin Tel. (0049 30) 314-25193, Fax: (0049 30) 314-21695 deuschel@math. tu-berlin. de 2 1 Mathematisches Institut, Bismarckstr. 1, D-91054 Erlangen, 2 Tel. (0049 9131) 85-22454, Fax (0049 9131) 85-26214 This volume collects original work and reviews on work in the ?eld of pro- bilitywhichtookplacewithintheframeworkoftheDFG-Schwerpunkt: Int- acting stochastic systems of high complexity. This research network started in May 1997 and was funded till May 2003. In this network between 20-30 (depending on the 2-year periods of grant renewal) groups from probab- ity, statistical physics and mathematical statistics within Germany were - tive. An extensive international collaboration was an essential part of this network and here particularly intense contacts were built up between the DFG-Schwerpunkt and EURANDOM, a European institute for research in stochastics, which was founded in 1997. This partnership reached from joint workshops and colloquia to collaborations on speci?c projects. The key scienti?c idea which was behind the research network was to - plore and develop the connections between research in in?nite dimensional stochastic analysis, statistical physics (Gibbs measures, random media), s- tial population models from mathematical biology, complex models of ?n- cial markets or of stochastic models with interacting components in other sciences as for example in climatology."

The concept of entropy arose in the physical sciences during the nineteenth century, particularly in thermodynamics and statistical physics, as a measure of the equilibria and evolution of thermodynamic systems. Two main views developed: the macroscopic view formulated originally by Carnot, Clausius, Gibbs, Planck, and Caratheodory and the microscopic approach associated with Boltzmann and Maxwell. Since then both approaches have made possible deep insights into the nature and behavior of thermodynamic and other microscopically unpredictable processes. However, the mathematical tools used have later developed independently of their original physical background and have led to a plethora of methods and differing conventions.

The aim of this book is to identify the unifying threads by providing surveys of the uses and concepts of entropy in diverse areas of mathematics and the physical sciences. Two major threads, emphasized throughout the book, are variational principles and Ljapunov functionals. The book starts by providing basic concepts and terminology, illustrated by examples from both the macroscopic and microscopic lines of thought. In-depth surveys covering the macroscopic, microscopic and probabilistic approaches follow. Part I gives a basic introduction from the views of thermodynamics and probability theory. Part II collects surveys that look at the macroscopic approach of continuum mechanics and physics. Part III deals with the microscopic approach exposing the role of entropy as a concept in probability theory, namely in the analysis of the large time behavior of stochastic processes and in the study of qualitative properties of models in statistical physics. Finally in Part IV applications in dynamical systems, ergodic and information theory are presented.

The chapters were written to provide as cohesive an account as possible, making the book accessible to a wide range of graduate students and researchers. Any scientist dealing with systems that exhibit entropy will find the book an invaluable aid to their understanding.