Diffusion of active matter with inertia*

In this work we study the motion of active Brownian particles (ABPs) while keeping both translational and rotational inertia. Following a Langevin formalism, we theoretically find that whereas translational inertia does not play a role in the ABPs effective diffusion, rotational inertia is able to enhance the ABPs’ diffusion. To elucidate such a new effect, one has to properly take into account the rotational inertia contribution in the orientation correlations. The mean-square speed for this system is also studied and its dependence on translational and rotational inertias is determined theoretically. To validate our analytical results, Brownian dynamics simulations are performed.