Statistical Mechanics, 3 rd edition is an indispensable tool for postgraduate students of science and engineering. Since the first edition published in 1972, Raj Pathria has provided an invaluable resource for the study of physical properties on the basis of dynamical behaviour. The book is suitable for a two semester course, offering the theoretical formalism proven to be of immense value to the field of physics. The author has based the book on principles of mathematical statistics and Hamiltonian mechanics. By providing historical insight and approaching the subject uniformly, students are able further their studies of statistical mechanics into their professional careers.-Bose-Einstein condensation in atomic gases -Thermodynamics of the early universe -Computer simulations: Monte Carlo and molecular dynamics -Correlation functions and scattering -Fluctuation-dissipation theorem and the dynamical structure factor -Chemical equilibrium -Exact solution of the two-dimensional Ising model for finite systems -Degenerate atomic Fermi gases -Exact solutions of one-dimensional fluid models -Interactions in ultracold Bose and Fermi gases -Brownian motion of anisotropic particles and harmonic oscillators