麻豆AV

Theodore Kolokolnikov
Dalhousie University

Animal groups often form striking aggregation patterns. Examples include from schools of fish to locust swarms, to patterns in bacterial cultures. In this talk, we discuss a very simple model of swarming based on pairwise particle interactions with short-range attraction and long-range repulsion, which can lead to very complex and intriguing patterns in two dimensions. Depending on the relative strengths of attraction and repulsion, a multitude of various patterns are observed, from nearly-constant density swarms to annular solutions, to complex N-fold symmetry patterns. We show that annular-type patterns may form if short-range repulsion is sufficiently weak. A Turing-type analysis of such annular states further reveals a wealth of possible instabilities which often lead to complicated and beautiful patterns. We also consider an inverse problem: given a target pattern, how to custom-design the force interaction to obtain said pattern as a steady state.