Boltzmann's formula S = In(W(E) defines the microcanonical ensemble. The usual textbooks on statistical mechanics start with the microensemble but rather quickly switch to the canonical ensemble introduced by Gibbs. This has the main advantage of easier analytical calculations, but there is a price to pay -- for example, phase transitions can only be defined in the thermodynamic limit of infinite system size. The question how phase transitions show up from systems with, say, 100 particles with an increasing number towards the bulk can only be answered when one finds a way to define and classify phase transitions in small systems. This is all possible within Boltzmann's original definition of the microcanonical ensemble. Starting from Boltzmann's formula, the book formulates the microcanonical thermodynamics entirely within the frame of mechanics. This way the thermodynamic limit is avoided and the formalism applies to small as well to other nonextensive systems like gravitational ones. Phasetransitions of first order, continuous transitions, critical lines and multicritical points can be unambiguously defined by the curvature of the entropy S(E, N). Special attention is given to the fragmentation of nuclei and atomic clusters as a peculiar phase transition of small systems controlled, among others, by angular momentum. The dependence of the liquid-gas transition of small atomic clusters under prescribed pressure is treated. Thus the analogue to the bulk transition can be studied. New insights into the many facets of the many-body physics of the critical point are presented. The book also describes the microcanonical statistics of the collapse of a self-gravitating system under large angular momentum.

Boltzmann's formula S = In[W(E)] defines the microcanonical ensemble. The usual textbooks on statistical mechanics start with the microensemble but rather quickly switch to the canonical ensemble introduced by Gibbs. This has the main advantage of easier analytical calculations, but there is a price to pay — for example, phase transitions can only be defined in the thermodynamic limit of infinite system size. The question how phase transitions show up from systems with, say, 100 particles with an increasing number towards the bulk can only be answered when one finds a way to define and classify phase transitions in small systems. This is all possible within Boltzmann's original definition of the microcanonical ensemble.Starting from Boltzmann's formula, the book formulates the microcanonical thermodynamics entirely within the frame of mechanics. This way the thermodynamic limit is avoided and the formalism applies to small as well to other nonextensive systems like gravitational ones. Phase transitions of first order, continuous transitions, critical lines and multicritical points can be unambiguously defined by the curvature of the entropy S(E,N). Special attention is given to the fragmentation of nuclei and atomic clusters as a peculiar phase transition of small systems controlled, among others, by angular momentum.The dependence of the liquid-gas transition of small atomic clusters under prescribed pressure is treated. Thus the analogue to the bulk transition can be studied. The book also describes the microcanonical statistics of the collapse of a self-gravitating system under large angular momentum.

This monograph develops a unified microscopic basis for phases and phase changes of bulk matter and small systems, based on classical physics. It describes the thermodynamics of ensembles of particles and explains phase transition in gaseous and liquid systems. The origins are derived from simple but physically relevant models of how transitions occur between rigid and fluid states, of how phase equilibria arise, and how they differ for small and large systems.

This book is a printed edition of the Special Issue "Thermodynamics and Statistical Mechanics of Small Systems" that was published in Entropy

The book provides an introduction to the physics which underlies phase transitions and to the theoretical techniques currently at our disposal for understanding them. It will be useful for advanced undergraduates, for post-graduate students undertaking research in related fields, and for established researchers in experimental physics, chemistry, and metallurgy as an exposition of current theoretical understanding. - ;Recent developments have led to a good understanding of universality; why phase transitions in systems as diverse as magnets, fluids, liquid crystals, and superconductors can be brought under the same theoretical umbrella and well described by simple models. This book describes the physics underlying universality and then lays out the theoretical approaches now available for studying phase transitions. Traditional techniques, mean-field theory, series expansions, and the transfer matrix, are described; the Monte Carlo method is covered, and two chapters are devoted to the renormalization group, which led to a break-through in the field. The book will be useful as a textbook for a course in `Phase Transitions', as an introduction for graduate students undertaking research in related fields, and as an overview for scientists in other disciplines who work with phase transitions but who are not aware of the current tools in the armoury of the theoretical physicist. - ;Introduction; Statistical mechanics and thermodynamics; Models; Mean-field theories; The transfer matrix; Series expansions; Monte Carlo simulations; The renormalization group; Implementations of the renormalization group. -

This introductory level text addresses the broad range of nonequilibrium phenomena observed at short time scales. It focuses on the important questions of correlations and memory effects in dense interacting systems. Experiments on very short time scales are characterized, in particular, by strong correlations far from equilibrium, by nonlinear dynamics, and by the related phenomena of turbulence and chaos. The impressive successes of experiments using pulsed lasers to study the properties of matter and of the new methods of analysis of the early phases of heavy ion reactions have necessitated a review of the available many-body theoretical methods. The aim of this book is thus to provide an introduction to the experimental and theoretical methods that help us to understand the behaviour of such systems when disturbed on very short time scales.

This booklet is devoted to the thermodynamic and kinetic description of first-order phase transitions. In general, the matter of the world exists in different phases. Normally phase ctlanges take place in ther­ modynamic equilibrium, which will be considered here. Typically,the system is rapidly quenched from a one-phase thermal equilibrium state to a nonequilibrium situation. During the so-ca lIed equilibrium phase transformation process the quenched supersaturated system evolves from the nonequilibrium state to an equilibrium one which consists of two coexisting phases. In aseries of books on phase transitions and critical phenomena (DDMB, GREEN, lEBDWITZ, 1972 - 19B3) an immense amount of material to different aspects of ttlis topic is summarized. The other type of phase transitions takes place in systems far from equilibrium. Due to 'the nonequi1ibrium boundary conditions and the flu­ xes from the environment into the system the final state of this so­ called nonequilibrium phase transition is a stable nonequilibrium si­ tuation. Such interesting processes (e. g. pattern formation, multista­ bi1ity) do not appear only in physics but also in chemistry, meteorolo­ gy, biology and many areas of engineering. Concerning questions in this context we recommend the reader to the monographs by HAKEN (197B), and EBElING, FEISTEl (1982). An overview of the problems of recent interest in this field is given in the Proceedings of the Third International Conference on Irreversible Processes and Dissipative Structures, edited by EBElING and Ul8RICHT (1986).