Abstract

Most examples of collections of moving biological entities—from cells, to insects and vertebrates—take place in heterogeneous, disodered, environments. Despite of this, most experimental and theoretical efforts have focused on the transport properties in homogeneous media. The impact of environmental heterogeneities has remained poorly explored. Here, we will see that the transport properties in heterogeneous media is fundamentally different from the one in homogenous environments. For instance, in heterogeneous environments, spontaneous particle trapping of particles and sub-diffusion can occur, while long-range order of two-dimensional polar active liquids is not possible. Furthermore, in the absence of dynamic noise, it is possible to show that when the equations of motion exhibit a Hamiltonian structure, particle trapping cannot occur, while the presence of attractors in these equations indicate the asymptotic convergence of particle trajectories to bounded areas in space, i.e. traps. References:

Pattanayak, Aranson, Peruani, in preparation (2023) Rahmani, Peruani, Romanczuk, Commun Phys 4, 206 (2021) Peruani and Aranson, Phys. Rev. Lett. 120, 238101 (2018) Chepizhko and Fernando Peruani, Phys. Rev. Lett. 111, 160604 (2013) Chepizhko, E.G. Altmann, and F. Peruani, Phys. Rev. Lett. 110, 238101 (2013)