title: Spectral problem for dilute atomic gases using discrete Uhling-Uhlenbeck operators.
abstract: Effects of free orientations (theta which is related to the relative direction of scattering of particles with respect to the normal of the propagating plane-wave front) using four-velocity model for the dispersion relationship of ultrasound propagation in dilute atomic (hard-sphere particles of Bose and Fermi statistics) gases are presented. We address the dispersion relations thus obtained by the relevant parameter rho (a blocking factor) or B which describes the Bose and Fermi particles for the quantum analog of the discrete Boltzmann system when B is positive (and rho=1) and negative (and rho=-1), respectively. The preliminary results show that there is no attenuation when the parameter theta equals pi/4 for all Bs.
authors.affiliation: Department of Physics, Northwest Normal University, Gansu, Lanzhou 730070, China.
authors.forename: A Kwang-Hua
authors.initials: AK
authors.lastname: Chu