Active Brownian particles in external force fields: field-theoretical models, generalized barometric law, and programmable density patterns
This work develops a predictive field theory for interacting active Brownian particles (ABPs) in 2D and 3D under external forces like gravity or harmonic traps. It derives a generalized barometric formula for gravity and shows that an external trap can induce motility-induced phase separation, enabling programmable density patterns in active matter.