Weakly interacting Bose gas
In condensed matter physics, a weakly interacting Bose gas is a quantum mechanical system composed of bosons that interact through low-strength, typically repulsive short-range forces. Unlike the ideal Bose gas, which neglects all interactions, the weakly interacting Bose gas provides a more realistic model for understanding Bose–Einstein condensation and superfluidity.
Source: Wikipedia — Weakly interacting Bose gas (CC BY-SA 4.0)