Hydrodynamic Fluctuations and Instabilities in Ordered Suspensions of SelfPropelled Particles
Abstract
We construct the hydrodynamic equations for suspensions of selfpropelled particles (SPPs) with spontaneous orientational order, and make a number of striking, testable predictions: (i)Nematic SPP suspensions are always absolutely unstable at long wavelengths. (ii)SPP suspensions support novel propagating modes at long wavelengths, coupling orientation, flow, and concentration. (iii)In a wave number regime accessible only in low Reynolds number systems such as bacteria, polarordered suspensions are invariably convectively unstable. (iv)The variance in the number N of particles, divided by the mean <N> , diverges as <N >^{2/3 } in polarordered SPP suspensions.
 Publication:

Physical Review Letters
 Pub Date:
 July 2002
 DOI:
 10.1103/PhysRevLett.89.058101
 arXiv:
 arXiv:condmat/0108301
 Bibcode:
 2002PhRvL..89e8101A
 Keywords:

 87.10.+e;
 General theory and mathematical aspects;
 Condensed Matter  Soft Condensed Matter;
 Condensed Matter  Statistical Mechanics;
 Quantitative Biology  Quantitative Methods
 EPrint:
 submitted to Phys Rev Lett