题目：Beliaev Damping Through Friedrichs Model

报告人：李奔 副教授 （浙江万里学院）

地点：致远楼101室

时间：2024年9月4日 10:00-11:00

摘要: We consider the Bose gas at zero temperature. According to Bogoliubov theory the low energy behaviour of the system is described by non-interacting bosonic quasiparticles called phonons. In this presentation we show how the mechanism of Beliaev damping - the decay of phonons due to interactions between them - can be explained using an effective theory based on the Friedrichs model approach. This allows us to formulate in a rigorous way a theorem that describes this phenomenon. In particular, we compute the damping ratio of phonons - a result first derived by S.T. Beliaev using diagrammatic techniques.  Joint work with Jan Derezinski and Marcin Napiorkowski.

All are welcome!