A large-scale system consisting of self-propelled particles, moving under the directional alignment rule (DAR), can often self-organize to an ordered state that emerges from an initially rotationally symmetric configuration. It is commonly accepted that the DAR, which leads to effective long-range interactions, is the underlying mechanism contributing to… (More)

@article{Li2008SingularitiesAS,
title={Singularities and symmetry breaking in swarms.},
author={Wei Li and Hai-Tao Zhang and Michael Q. Chen and Tao Zhou},
journal={Physical review. E, Statistical, nonlinear, and soft matter physics},
year={2008},
volume={77 2 Pt 1},
pages={021920}
}