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Updated: Mar 13, 2026

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Large deviations of the current for driven periodic diffusions
Pelerine Tsobgni Nyawo1, Hugo Touchette1,2
1Institute of Theoretical Physics, Department of Physics, University of Stellenbosch, Stellenbosch 7600, South Africa.
Abstract:
We study the large deviations of the time-integrated current for a driven diffusion on the circle, often used as a model of nonequilibrium systems. We obtain the large deviation functions describing the current fluctuations using a Fourier-Bloch decomposition of the so-called tilted generator, and we also construct from this decomposition the effective (biased, auxiliary, or driven) Markov process describing the diffusion as current fluctuations are observed in time. This effective process provides a clear physical explanation of the various fluctuation regimes observed. It is used here to obtain an upper bound on the current large deviation function, which we compare to a recently derived entropic bound, and to study the low-noise limit of large deviations.
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