Long-lived giant number fluctuations in a swarming granular nematic

Narayan, Vijay and Ramaswamy, Sriram and Menon, Narayanan (2007) Long-lived giant number fluctuations in a swarming granular nematic. In: Science, 317 (5834). pp. 105-108.

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Abstract

Coherently moving flocks of birds, beasts, or bacteria are examples of living matter with spontaneous orientational order. How do these systems differ from thermal equilibrium systems with such liquid crystalline order? Working with a fluidized monolayer of macroscopic rods in the nematic liquid crystalline phase, we find giant number fluctuations consistent with a standard deviation growing linearly with the mean, in contrast to any situation where the central limit theorem applies. These fluctuations are long-lived, decaying only as a logarithmic function of time. This shows that flocking, coherent motion, and large-scale inhomogeneity can appear in a system in which particles do not communicate except by contact.

Item Type:	Journal Article
Publication:	Science
Publisher:	American Association for the Advancement of Science
Additional Information:	Copyright of this article belongs to American Association for the Advancement of Science.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	29 Mar 2010 11:12
Last Modified:	19 Sep 2010 05:57
URI:	http://eprints.iisc.ac.in/id/eprint/26299

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