Phase coherence among the Fourier modes and non-Gaussian characteristics in the Alfvén chaos system

Yasuhiro Nariyuki, Makoto Sasaki, Naohiro Kasuya, Tohru Hada, Masatoshi Yagi

Research output: Contribution to journalArticlepeer-review

Abstract

Non-Gaussian characteristics in time series of the Alfven chaos system are discussed. The phase coherence index, a measure defined by using the surrogate data method and the structure function, is used to evaluate the phase coherence among the Fourier modes. Through Monte Carlo significance testing, it is found that the phase coherence decays monotonically with increasing dissipative parameter and time scale. By applying the Mori projection operator method assuming the Markov process, a model equation for the time correlation function is derived from the generalized Langevin equation. As opposed to the result of the phase coherence analysis, it is concluded that the difference between the direct numerical simulation and the model equation becomes pronounced as the dissipative parameters are increased. This suggests that, even when the phase coherence index is not significant, the underlying physical system may be a non-Gaussian process.

Original languageEnglish
Article number033J01
JournalProgress of Theoretical and Experimental Physics
Volume2017
Issue number3
DOIs
Publication statusPublished - Mar 1 2017

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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