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arXiv · 1507.04226

Fluctuation relations for anomalous dynamics generated by time-fractional Fokker-Planck equations

P. Dieterich·R. Klages·A. V. Chechkin
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Abstract

Anomalous dynamics characterized by non-Gaussian probability distributions (PDFs) and/or temporal long-range correlations can cause subtle modifications of conventional fluctuation relations. As prototypes we study three variants of a generic time-fractional Fokker-Planck equation with constant force. Type A generates superdiffusion, type B subdiffusion and type C both super- and subdiffusion depending on parameter variation. Furthermore type C obeys a fluctuation-dissipation relation whereas A and B do not. We calculate analytically the position PDFs for all three cases and explore numerically their strongly non-Gaussian shapes. While for type C we obtain the conventional transient work fluctuation relation, type A and type B both yield deviations by featuring a coefficient that depends on time and by a nonlinear dependence on the work. We discuss possible applications of these types of dynamics and fluctuation relations to experiments.

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P. Dieterich, R. Klages, A. V. Chechkin. 2015-07-15. Fluctuation relations for anomalous dynamics generated by time-fractional Fokker-Planck equations. https://doi.org/10.1088/1367-2630%2F17%2F7%2F075004

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