Certain systems consisting of a one-dimensional gas of a finite number of point particles interacting with a “hard-core” potential are considered.

On établit selon les méthodes cinétiques de l'Ecole de Bruxelles et pour un potentiel en P2 l'équation d'évolution pour le retour à l'équilibre au second order dans la perturbation de la fonction de distribution en énergie à une particule dans un fluide isotrope de bâtonnets minces. On...

The non-linear response of the exciton system is considered and non-equilibrium exciton populations are calculated. It is shown that in the high frequency domain (ω > ωc ≈ 10-13 s-1) the role and the influence of the external perturbation on the exciton population becomes unimportant.

We reconsider the problem of calculating electrostatic lattice potentials, or in fact potentials of the type |r|βφl(r), where φl(r) is the lth derivative of the l/|r|p potential. According to Ewald, and generalized by Nijboer and de Wette, the slowly converging potential can be expressed in...

We report high precision measurements of the self-diffusion coefficient of Kr performed along the isotherm T = 293 K, in the density range 0.03–0.12 g/cm3. The first correction term of the expansion of ϱD in powers of density is obtained and compared with the result for a hard-sphere fluid.

The kinematic interaction of spin-waves is found to lead to additional energy levels even in the presence of an interaction of spin-waves with mechanical vibrations of the crystal molecules. Those levels appear in the region of large wave-vectors k 107cm−1. The lower limit of this interval is...

We have obtained the exact numerical results of the specific heat, the susceptibility and the correlation functions L0(T) and L1(T) for finite extended Hubbard rings at the large U limit. It is shown that the nearest neighbor interactions favor the ferromagnetic ordering. When the number of...

Transition probabilities for the processes vv↔vv, vv̄, vv↔vv, and spin-dependent transition amplitudes for the processes ve↔ve, vē↔vē, v̄e↔v̄e, ve↔ve and vv̄↔eē are calculated in lowest order for the Weinberg-Salam model.

We consider a finite, thermally isolated, classical system which passes from an equilibrium state A by the removal of an internal constraint to another equilibrium state B after an empirical relaxation time. In the phase space of the system, cells are introduced according to the set of measuring...

The normal-superfluid phase-transition temperature of a dilute Bose system whose particles interact via a two-body potential composed of a hard core followed by a weak attractive tail is studied using the three-level approximation. It is found that, for such a system, the three-level...