The force distribution function of an oscillator model of polymer stretching at constant velocity

Sharma, Rati and Cherayil, Binny J (2012) The force distribution function of an oscillator model of polymer stretching at constant velocity. In: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT .

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Abstract

Recent simulations of the stretching of tethered biopolymers at a constant speed v (Ponmurugan and Vemparala, 2011 Phys. Rev. E 84 060101(R)) have suggested that for any time t, the distribution of the fluctuating forces f responsible for chain deformation is governed by a relation of the form P(+ f)/ P(- f) = expgamma f], gamma being a coefficient that is solely a function of v and the temperature T. This result, which is reminiscent of the fluctuation theorems applicable to stochastic trajectories involving thermodynamic variables, is derived in this paper from an analytical calculation based on a generalization of Mazonka and Jarzynski's classic model of dragged particle dynamics Mazonka and Jarzynski, 1999 arXiv:cond-\textbackslashmat/9912121v1]. However, the analytical calculations suggest that the result holds only if t >> 1 and the force fluctuations are driven by white rather than colored noise; they further suggest that the coefficient gamma in the purported theorem varies not as v(0.15)T-(0.7), as indicated by the simulations, but as vT(-1).

Item Type:	Journal Article
Publication:	JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
Publisher:	IOP PUBLISHING LTD
Additional Information:	Copyright for this article belongs to IOP Publishing LTD
Keywords:	exact results; fluctuations (theory); stochastic processes (theory)
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	14 Jul 2012 07:17
Last Modified:	14 Jul 2012 07:17
URI:	http://eprints.iisc.ac.in/id/eprint/44810

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