Collective and emergent dynamics in active systems

Abstract

We study some non-equilibrium properties of active matter, such as self-propulsion, that causes the emergence of phenomena not observed in equilibrium systems. By applying the UCNA approximation we are able to derive a probability density function under stationary conditions that enables us to study the behaviour of active particles in the presence of a perturbation such as a hard wall modelled by a repulsive potential. From here, we calculate the adsorption near the wall and we study the dependence it has on activity. We find that adsorption grows approximately as the square root of the activity, regardless if the potential is strictly repulsive or repulsive and attractive in different regions of space