We examine three exactly soluble models for systems undergoing a structural phase transition. Two models are described by a lattice-dynamic hamiltonian, the phase transition being driven by a spherical constraint in one case and by a long-range anharmonic interaction in the other. Finally, we...

A new method of the determination of the Liouville operator for the step-type interparticle interaction is presented. The interaction part of the Liouville operator is calculated for the particles interacting via a spherical repulsive and spherical attractive barrier. Limiting cases of an...

Using the linearized system of equations due to de Groot and Mazur governing the acoustic non-equilibrium phenomena in a viscous, heat-conducting gas, we have in this paper given an exhaustive treatment of the problem of wave propagation. More specifically, the normal mode analysis brings out a...

The closure relation for a correlation function of third order suggested by Schwartz and Ehrenreich in the framework of the electron theory of liquid metals is substituted into the formal relation connecting g(2) with g(3). The equation determining the radial distribution function, obtained in...

The entropy balance equation is derived for a system of unstable particles in the Markovian approximation using the Gibbs-von Neumann form of entropy. The results for the entropy production and the entropy flow are finite if the initial state of the decay products is not a pure vacuum state.

Gradients in the stream velocity of a gas consisting of optically anisotropic molecules give rise to an alignment of rotational angular momenta. This alignment can be observed as a birefringence in the gas. The results of such measurements are reported in this paper and interpreted within the...

Microscopic expressions for the long-wavelength excitations of a classical electron gas have been established valid to all orders in the density, charge and plasma expansion parameter. The strengths with which these excitations appear in various space-time autocorrelation functions have also...

MFA Lorentz field and Lines transition temperature concepts are analysed for the transverse Ising model with an interaction of dipolar nature when applied to KDP-like ferroelectrics.

Certain problems in physics and chemistry lead to the definition of a class of stochastic processes. Although they are not Markovian they can be treated explicitly to some extent. In particular, the probability distribution for large times can be found. It is shown to obey a master equation....