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Active nematics on a substrate: giant number fluctuations and long-time tails

Sriram Ramaswamy·R. Aditi Simha·John Toner
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Abstract

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 and (ii) long-time tails $\sim t^{-d/2}$ in the autocorrelation of the particle velocities in $d$ dimensions 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.

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Sriram Ramaswamy, R. Aditi Simha, John Toner. 2002-08-29. Active nematics on a substrate: giant number fluctuations and long-time tails. https://doi.org/10.1209/epl%2Fi2003-00346-7

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