title: Relevance of metric-free interactions in flocking phenomena.
abstract: We show that the collective properties of self-propelled particles aligning with their topological (Voronoi) neighbors are qualitatively different from those of usual models where metric interaction ranges are used. This relevance of metric-free interactions, shown in a minimal setting, indicate that realistic models for the cohesive motion of cells, bird flocks, and fish schools may have to incorporate them, as suggested by recent observations.
authors.affiliation: Service de Physique de l'État Condensé, CEA-Saclay, 91191 Gif-sur-Yvette, France.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ginelli
authors.forename: Hugues
authors.initials: H
authors.lastname: Chaté
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001717:Birds / Q000502:physiology; D002449:Cell Aggregation; D005399:Fishes / Q000502:physiology; D008954:Models, Biological; D013997:Time Factors