title: Scale-invariant correlations in dynamic bacterial clusters.
abstract: In Bacillus subtilis colonies, motile bacteria move collectively, spontaneously forming dynamic clusters. These bacterial clusters share similarities with other systems exhibiting polarized collective motion, such as bird flocks or fish schools. Here we study experimentally how velocity and orientation fluctuations within clusters are spatially correlated. For a range of cell density and cluster size, the correlation length is shown to be 30% of the spatial size of clusters, and the correlation functions collapse onto a master curve after rescaling the separation with correlation length. Our results demonstrate that correlations of velocity and orientation fluctuations are scale invariant in dynamic bacterial clusters.
authors.affiliation: Department of Physics and Institute of Natural Sciences, Shanghai Jiao Tong University, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Xu
authors.initials: X
authors.lastname: Dong
authors.forename: Avraham
authors.initials: A
authors.lastname: Be'er
authors.forename: Harry L
authors.initials: HL
authors.lastname: Swinney
authors.forename: H P
authors.initials: HP
authors.lastname: Zhang
mesh_terms: D001412:Bacillus subtilis / Q000502:physiology*; D001422:Bacterial Adhesion; D018407:Bacterial Physiological Phenomena; D008954:Models, Biological; D053038:Quorum Sensing / Q000502:physiology*