Beliaev damping in Bose gas
arXiv:2310.20070 · doi:10.1007/s10955-024-03328-2
Abstract
According to the Bogoliubov theory the low energy behaviour of the Bose gas at zero temperature can be described by non-interacting bosonic quasiparticles called phonons. In this work the damping rate of phonons at low momenta, the so-called Beliaev damping, is explained and computed with simple arguments involving the Fermi Golden Rule and Bogoliubov's quasiparticles.
27 pages, 2 figures, revised version