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arXiv · 1203.6853

Continuous theory of active matter systems with metric-free interactions

Anton Peshkov·Sandrine Ngo·Eric Bertin·Hugues Chaté·Francesco Ginelli
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Abstract

We derive a hydrodynamic description of metric-free active matter: starting from self-propelled particles aligning with neighbors defined by "topological" rules, not metric zones, -a situation advocated recently to be relevant for bird flocks, fish schools, and crowds- we use a kinetic approach to obtain well-controlled nonlinear field equations. We show that the density-independent collision rate per particle characteristic of topological interactions suppresses the linear instability of the homogeneous ordered phase and the nonlinear density segregation generically present near threshold in metric models, in agreement with microscopic simulations.

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Anton Peshkov, Sandrine Ngo, Eric Bertin, Hugues Chaté, Francesco Ginelli. 2012-03-30. Continuous theory of active matter systems with metric-free interactions. https://doi.org/10.1103/physrevlett.109.098101

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