2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/19293We study the process of scattering of two impurity atoms accompanied by generation of an elementary excitation in a surrounding Bose--Einstein condensate. This process, unlike the phonon generation by a {\it single} impurity atom, has no velocity threshold and can be regarded as a quantum acoustic analog of a bremsstrahlung in quantum electrodynamics.4 pages, 1 figureStatistical Mechanicstext