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arXiv · 0803.0431

Scale-free vortex cascade emerging from random forcing in a strongly coupled system

Kristoffer Rypdal·Boris Kozelov·Svetlana Ratynskaia·Boris Klumov·Christina Knapek
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Abstract

The notions of self-organised criticality (SOC) and turbulence are traditionally considered to be applicable to disjoint classes of phenomena. Nevertheless, scale-free burst statistics is a feature shared by turbulent as well as self-organised critical dynamics. It has also been suggested that another shared feature is universal non-gaussian probability density functions (PDFs) of global fluctuations. Here, we elucidate the unifying aspects through analysis of data from a laboratory dusty plasma monolayer. We compare analysis of experimental data with simulations of a two-dimensional (2D) many-body system, of 2D fluid turbulence, and a 2D SOC model, all subject to random forcing at small scales. The scale-free vortex cascade is apparent from structure functions as well as spatio-temporal avalanche analysis, the latter giving similar results for the experimental and all model systems studied. The experiment exhibits global fluctuation statistics consistent with a non-gaussian universal PDF, but the model systems yield this result only in a restricted range of forcing conditions.

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Kristoffer Rypdal, Boris Kozelov, Svetlana Ratynskaia, Boris Klumov, Christina Knapek. 2008-03-04. Scale-free vortex cascade emerging from random forcing in a strongly coupled system. https://doi.org/10.1088/1367-2630%2F10%2F9%2F093018

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