Humans, ants and active particles all form pathways in their environment to enable more efficient navigation. Active particles have been shown to create and reuse tunnels in a sea of passive obstacles, leading to the formation of large, organized structures (clusters). The stability and dynamics of these structures depends on the particle size, as does the lifetime of the surrounding tunnels. When particles are small, they form clusters that spontaneously rotate. When they are large, clusters are expected to lose this rotational stability.

In this project, we will try to elucidate how the size and dynamics of clusters depends on the particle (and obstacle) size. To do so, we will use a dimensionless numerical simulation and systematically vary the particle size as well as the density of obstacles to map the phase space and better understand the behavior of this system.