A note on the calculation of the long-wavelength limit of the bosonic excitation spectrum
arXiv:1405.6839 · doi:10.1515/zna-2014-0211
Abstract
An approach is proposed to analyze an interacting bosonic system using two-time temperature Green's functions on the collective variables. Two systems are studied: liquid helium-4 and the Yukawa Bose-liquid being a model of the nuclear matter. The suggested decoupling in the equations of motion for Green's functions yields a good description of the elementary excitation spectrum in the long-wavelength limit.
11 pages, 2 figures