English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We derive the mean field kinetic equation for the momentum distribution ofBogoliubov excitations (bogolons) in a spatially uniform Bose-Einsteincondensate (BEC), with a focus on the collision integrals. We use the method ofPeletminksii and Yatsenko rather than the standard non-equilibrium Green'sfunction formalism. This method produces three collision integrals ${\calG}^{12}$, ${\cal G}^{22}$ and ${\cal G}^{31}$. Only ${\cal G}^{12}$ and ${\calG}^{22}$ have been considered by previous authors. The third collision integral${\cal G}^{31}$ contains the effects of processes where one bogolon becomesthree and vice versa. These processes are allowed because the total number ofbogolons is not conserved. Since ${\cal G}^{31}$ is of the same order in theinteraction strength as ${\cal G}^{22}$, we predict that it will significantlyinfluence the dynamics of the bogolon gas, especially the relaxation of thetotal number of bogolons to its equilibrium value.

Collision Integrals in the Kinetic Equations of dilute Bose-Einstein Condensates