Symmetry properties of the large-deviation function of the velocity of a self-propelled polar particle

Kumar, Nitin ; Ramaswamy, Sriram ; Sood, A. K. (2011) Symmetry properties of the large-deviation function of the velocity of a self-propelled polar particle Physics Review Letters, 106 (11). pp. 118001-118004. ISSN 0031-9007

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Official URL: http://prl.aps.org/abstract/PRL/v106/i11/e118001

Related URL: http://dx.doi.org/10.1103/PhysRevLett.106.118001

Abstract

A geometrically polar granular rod confined in 2-D 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:Article
Source:Copyright of this article belongs to The American Physical Society.
ID Code:40163
Deposited On:21 May 2011 10:59
Last Modified:17 May 2016 22:21

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