Active nematics on a substrate: Giant number fluctuations and long-time tails
Centre for Condensed-Matter Theory, Department of
Physics Indian Institute of Science - Bangalore 560 012, India
2 Department of Physics, University of Oregon - Eugene, OR 94703, USA
Accepted: 18 February 2003
We construct the equations of motion for the coupled dynamics of order parameter and concentration for the nematic phase of driven particles on a solid surface, and show that they imply i) giant number fluctuations, with a standard deviation proportional to the mean in dimension d = 2 of primary relevance to experiment, and ii) long-time tails in the autocorrelation of the particle velocities despite the absence of a hydrodynamic velocity field. Our predictions can be tested in experiments on aggregates of amoeboid cells as well as on layers of agitated granular matter.
PACS: 05.70.Ln – Nonequilibrium and irreversible thermodynamics / 87.18.Ed – Aggregation and other collective behavior of motile cells / 45.70.-n – Granular systems
© EDP Sciences, 2003