TY - JOUR
T1 - Phase coherence among the Fourier modes and non-Gaussian characteristics in the Alfvén chaos system
AU - Nariyuki, Yasuhiro
AU - Sasaki, Makoto
AU - Kasuya, Naohiro
AU - Hada, Tohru
AU - Yagi, Masatoshi
N1 - Publisher Copyright:
© The Author(s) 2017.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - 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.
AB - 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.
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U2 - 10.1093/ptep/ptx016
DO - 10.1093/ptep/ptx016
M3 - Article
AN - SCOPUS:85017096953
VL - 2017
JO - Progress of Theoretical and Experimental Physics
JF - Progress of Theoretical and Experimental Physics
SN - 2050-3911
IS - 3
M1 - 033J01
ER -