Natural time analysis of critical phenomena

作者：Varotsos Panayiotis; Sarlis Nicholas V; Skordas Efthimios S; Uyeda Seiya^*; Kamogawa Masashi

来源：Proceedings of the National Academy of Sciences of the United States of America, 2011, 108(28): 11361-11364.

DOI：10.1073/pnas.1108138108

• short-term earthquake prediction
• dynamic exponent
• fractional Gaussian noise
• fractional Brownian motion
• Burridge-Knopoff &quot
• train&quot
• model

A quantity exists by which one can identify the approach of a dynamical system to the state of criticality, which is hard to identify otherwise. This quantity is the variance kappa(1)(equivalent to <chi(2)> - <chi >(2)) of natural time chi, where hf < f(chi)>- Sigma p(k)f(chi(k)) and p(k) is the normalized energy released during the kth event of which the natural time is defined as chi(k) = k/N and N stands for the total number of events. Then we show that kappa(1) becomes equal to 0.070 at the critical state for a variety of dynamical systems. This holds for criticality models such as 2D Ising and the Bak-Tang-Wiesenfeld sandpile, which is the standard example of self-organized criticality. This condition of kappa(1) = 0.070 holds for experimental results of critical phenomena such as growth of rice piles, seismic electric signals, and the subsequent seismicity before the associated main shock.

• 出版日期2011-7-12