Symmetry Properties of the Large-Deviation Function of the Velocity of a Self-Propelled Polar Particle

Kumar, Nitin and Ramaswamy, Sriram and Sood, AK (2011) Symmetry Properties of the Large-Deviation Function of the Velocity of a Self-Propelled Polar Particle. In: Physical Review Letters, 106 (11).

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Abstract

A geometrically polar granular rod confined in 2D geometry, subjected to a sinusoidal vertical oscillation, undergoes noisy self-propulsion in a direction determined by its polarity. When surrounded by a medium of crystalline spherical beads, it displays substantial negative fluctuations in its velocity. We find that the large-deviation function (LDF) for the normalized velocity is strongly non-Gaussian with a kink at zero velocity, and that the antisymmetric part of the LDF is linear, resembling the fluctuation relation known for entropy production, even when the velocity distribution is clearly non-Gaussian. We extract an analogue of the phase-space contraction rate and find that it compares well with an independent estimate based on the persistence of forward and reverse velocities.

Item Type:	Journal Article
Publication:	Physical Review Letters
Publisher:	The American Physical Society
Additional Information:	Copyright of this article belongs to The American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	30 Mar 2011 08:27
Last Modified:	30 Mar 2011 08:27
URI:	http://eprints.iisc.ac.in/id/eprint/36336

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