Document 
Eur. Phys. J. E 26, 103-113 (2008)
DOI: 10.1140/epje/i2007-10295-y
Hydrodynamic regimes of active rotators at fluid interfaces
I. Llopis and I. PagonabarragaDepartament de Fisica Fonamental, Universitat de Barcelona, C. Marti i Franqués 1, 08028, Barcelona, Spain
ignacio@ffn.ub.es
Received 31 October 2007 / Published online 9 April 2008
Abstract
We analyze the collective motion of suspensions of active rotators at low Reynolds numbers which interact hydrodynamically. We introduce a simple model for a rotator which allows us to classify the relevant dynamical regimes of the suspension. We characterize the collective velocity at which rotators displace and analyze its implications at long times, when these rotator suspensions diffuse. We analyze the differences with respect to diffusion in suspensions of passive particles, and assess the relevance of the Stokes-Einstein relation on rotators' diffusivity.
PACS05.10.-a - Computational methods in statistical physics and nonlinear dynamics.
87.19.rs - Movement.
87.18.Gh - Cell-cell communication; collective behavior of motile cells. Correspondence: ignacio@ffn.ub.es
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2008