We express an exact formulation for an interacting Bose system as a functional integration over complex functions. We propose a modification of the generating functional which leads to different limiting processes. The present article rests upon Bogoliubov's description on the explanation of the...

We study the thermal fluctuations of density and flow velocity of particles diffusing in a non-uniform medium with memory character. The fluctuation spectra are derived from the macroscopic equations with the aid of the generalized Nyquist theorem. A comparison is made with other methods.

Rigorous results are obtained for the equilibrium properties of a model due to Falk and Ruijgrok in which a system of M chains of Ising spins have long-range equal-strengths interactions between nearest-neighbour chains only.

A mixed representation is proposed in which momentum directions, energy fractions, and a position projection of all the particles, are specified. It is based on the Radon transform if the number of particles is odd, and on a generalized Euler transform if it is even.

A previously-developed second quantization representation for nonrelativistic systems of composite particles is extended to include unstable composites. This representation explicitly exhibits the kinematics and dynamics of the decay of an unstable composite particle into smaller stable and/or...

Preliminary measurements of the nonequilibrium velocity distribution function in a heat conducting gas have been carried out using a Doppler broadened absorption line. The experimental technique, which uses the coincidence of a Stark tunable line of NH2D and the CO2 P(20) laser frequency, is...

The general scaling theory of transient phenomena near the instability point proposed by one of the authors (M.S.) is applied to analyze the transient behavior of laser radiation from the unstable state (i.e., no photon at the initial time). The analytic results thus obtained by the scaling...

The isotropic bundle representations of the Galilei group and its central extension are classified, and the natural cross-section, action of the group on the base manifold and the canonical cocyle are determined for all cases. Projective bundle representations of the Galilei group are defined...