The stochastic model for liquids, developed previously and applied to the evaluation of static correlations, is extended to the evaluation of the dynamic pair correlation function. This extension can be achieved by a generalization of the width function W, characterizing the spread in the...

A generalized critical point can be characterized by non-linear dynamics. We formulate the deterministic and stochastic theory of relaxation at such a point. Canonical problems are used to motivate the general solutions. In the deterministic theory, we show that at the critical point certain...

The kinetic equation of an inhomogeneous relativistic plasma, consisting of an electron gas and a radiation field, is studied with particular regard to its eigenvalues in the hydrodynamical limit. The treatment is classical for the particles and quantum-mechanical for the field oscillators.

A formalism is presented by which the linear relaxational behaviour of thermodynamic systems can be described. Instead of using the concept of internal variables of state a set of so-called constraint equations is introduced. These equations represent structural properties of the system and turn...

The exact result for the free energy per particle in systems described by a hamiltonian of the type NP(VN), where NVN denotes a set of short-range operators, is reformulated in terms of a convex-envelope construction. A comparison is given with results obtained for classical systems with...

A simple derivation is given for the mobility of Brownian particles in a periodic potential in the overdamped regime. The method makes use of the fact that the steady state current density, in response to a uniform external force, is uniform in space and can be expressed as a product of the...

The present work is devoted to the following question: What is the relation between the deterministic laws of dynamics and probabilistic description of physical processes?

Seven coefficients in the high temperature series expansions for the zero-field susceptibility and the specific heat are derived for the planar classical Heisenberg model with biquadratic interactions. The critical temperatures and the susceptibility exponents are determined for cubic lattices.

The probability of absorption as well as the mean absorption time and its variance, have been calculated for a model which does not satisfy detailed balance. The explicit calculation of the variance is helpful in understanding the different predictions between the deterministic and the...

We have calculated the velocities of the first and second sound and the structure factor for a system of interacting bosons. The two-body interatomic potential used is assumed to be composed of a hard core followed by a sum of both repulsive and attractive gaussians.