Studies in Statistical Mechanics, Volume VII: Fluctuation Phenomena Fluctuation explores different aspects of fluctuation behavior and their relation to microscopic processes and other phenomena, including the nucleation of a new phase following the quenching of a system into the coexistence region. It looks at phenomenological fluctuation theories, stochastic processes such as Markoff and momentless processes, and stochastic geometric aspects of amorphous solids. Comprised of five chapters, this volume begins with an overview of fluctuations and the Ehrenfest dog-flea model. It then turns to a discussion of density fluctuations in dilute gases, the Langevin theory of Brownian motion, and classical diffusion and random walks. It also systematically introduces the reader to the statistical mechanical theory of the kinetics of phase transitions, the molecular theory of metastability, and multidimensional continuous time random walks, along with the effect of boundaries and defects onf stochastic processes. In addition, it describes the phenomenological theory of the kinetics of nucleation and its application to nucleation, spinodal decomposition, and condensation. Other chapters focus on a stochastic model for the kinetics of phase transitions, the physical ideas used in theories of metastability, and the importance of dynamics in the study of metastability. The book explains how to estimate the escape rate and describes the statistical mechanics of clusters before concluding with a discussion of slowly-varying ensembles. This book is a valuable resource for students, physicists, and researchers who want to gain more knowledge and learn about statistical mechanics in general and fluctuation phenomena in particular.

The physics of disordered systems has enjoyed a resurgence of interest in the last decade. New concepts such as weak localization, interaction effects and Coulomb gap, have been developed for the transport properties of metals and insulators. With the fabrication of smaller and smaller samples and the routine availability of low temperatures, new physics has emerged from the studies of small devices. The new field goes under the name "mesoscopic physics" and has rapidly developed, both experimentally and theoretically. This book is designed to review the current status of the field.Most of the chapters in the book are devoted to the development of new ideas in the field. They include reviews of experimental observations of conductance fluctuations and the Aharonov-Bohm oscillations in disordered metals, theoretical and experimental work on low frequency noise in small disordered systems, transmittancy fluctuations through random barriers, and theoretical work on the distribution of fluctuation quantities such as conductance. Two chapters are not connected directly to the mesoscopic fluctuations but deal with small systems. They cover the effects of Coulomb interaction in the tunneling through the small junctions, and experimental results on ballistic transport through a perfect conductor.