| 1. |
- Anderson, Johan, 1973, et al.
(författare)
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Self-organisation of random oscillators
- 2015
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Ingår i: Festival-de-Theorie.
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Konferensbidrag (refereegranskat)abstract
- A model for the stochastic passive advection - diffusion of a scalar with external forcing is further developed by introducing a non-linear phase coupling dynamic between the phases of the stochastic flow and the forcing. The model for the phase coupling dynamic follows the well known Kuramoto model of the limit cycle oscillators with an additional linear coupling term between the phasesthe two stochastic fields. The aim is to study the impact of a collective phase synchronization or self-organisation on the fluctuation level of the scalar through a simple stochastic passive advection - diffusion relation. The results shown here, present a significant impact of the collective phase synchronization on the correlation time of the fluctuations, and on the suppression of the fluctuation amplitudes. The model predicts that in the presence of an additional linear coupling between the phases of the two stochastic fields, the phase synchronizations leads to a localisation as well as strong suppression of the fluctuation amplitudes. While, in the a-synchronized state we observe a predator-prey behavior between the correlations of the two fields and time auto-correlation of the fluctuations decay with an oscillatory trend.
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| 2. |
- Moradi, Sara, 1981, et al.
(författare)
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Predator-prey model for the self-organization of stochastic oscillators in dual populations
- 2015
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Ingår i: Physical Review E. - 2470-0045 .- 2470-0053. ; 92:6, s. 062930-
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Tidskriftsartikel (refereegranskat)abstract
- A predator-prey model of dual populations with stochastic oscillators is presented. A linear cross-coupling between the two populations is introduced following the coupling between the motions of a Wilberforce pendulum in two dimensions: one in the longitudinal and the other in torsional plain. Within each population a Kuramoto-type competition between the phases is assumed. Thus, the synchronization state of the whole system is controlled by these two types of competitions. The results of the numerical simulations show that by adding the linear cross-coupling interactions predator-prey oscillations between the two populations appear, which results in self-regulation of the system by a transfer of synchrony between the two populations. The model represents several important features of the dynamical interplay between the drift wave and zonal flow turbulence in magnetically confined plasmas, and a novel interpretation of the coupled dynamics of drift wave-zonal flow turbulence using synchronization of stochastic oscillator is discussed.
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| 3. |
- Moradi, Sara, 1981, et al.
(författare)
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Self-organisation of random oscillators with Levy stable distributions
- 2015
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Ingår i: 8th CHAOS Conference in Henri Poincaré Institute, Paris France (26-29 May 2015).
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Konferensbidrag (refereegranskat)abstract
- A new possibility of self-organized behavior of stochastically driven oscillators is presented. It is shown that synchronization by Levy stable processes is significantly more efficient than that by oscillators with Gaussian statistics. The competition between organization and disorder is studied by considering an external noise with Levy characteristics where oscillation between synchrony and disorder can be found as well as competing self-organized sub-populations. Theimpact of outlier events from the tail of the distribution function was examined by artificiallyintroducing a few additional oscillators with very strong coupling strengths and it is found that remarkably even one such rare and extreme event may govern the long term behavior of the coupled system.
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