Statistical Mechanics of Many-Particle Systems

Abstract

Statistical mechanics is the branch of theoretical physics that attempts to predict, by starting at the level of atoms, molecules, spins, or other small “particles,” the bulk properties of systems in which a large number of these particles interact with one another. In other words, it links the microscopic properties of matter (molecular interactions and structure), as determined from the laws of quantum or classical mechanics, to its macroscopic properties (e.g., pressure of a liquid). The province of statistical physics is more general, extending to any situation in which one is interested in the collective behavior of interacting entities, from population dynamics through solids, liquids, and gases to cosmology as well as random heterogeneous materials. Systems composed of many interacting particles (albeit much larger than molecular dimensions) are often useful models of random heterogeneous materials, and thus one can exploit the powerful machinery of statistical mechanics to study such materials. Moreover, as we will see in subsequent chapters, the formalism of statistical mechanics can be extended to nonparticulate systems.