title: Vortex formation by active agents as a model for Daphnia swarming.
abstract: We propose a self-propelled particle model for the swarming of Daphnia that takes into account mutual repulsion and attraction to a center. Surprisingly, a vortex is formed only for an intermediate strength of propulsion. The phase diagram and the transitions between states with and without a vortex are analyzed, and the nature of the phase boundaries is discussed based on a linear stability analysis of the motion of individual swimmers. This allows us to identify various key parameters determining the characteristic features of the collective motion.
authors.affiliation: Fachbereich Physik, Philipps-Universität Marburg, Renthof 6, D-35032 Marburg, Germany. juergen.vollmer@physik.uni-marburg.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Vollmer
authors.forename: Attila Gergely
authors.initials: AG
authors.lastname: Vegh
authors.forename: Christoph
authors.initials: C
authors.lastname: Lange
authors.forename: Bruno
authors.initials: B
authors.lastname: Eckhardt
mesh_terms: D000818:Animals; D003621:Daphnia / Q000502:physiology*; D008954:Models, Biological; D009038:Motion; D013550:Swimming