第１１６回「非線形・統計力学とその周辺」セミナーのご案内

日時：２０１２年７月１１日（水）１４：４５−１６：１５

場所：京都大学工学部総合校舎２階２１３講義室（吉田キャンパス）

講演者： 佐藤 譲（北海道大学 電子科学研究所 / 理学院数学専攻）

講演題目：
Noise-induced phenomena in one-dimensional maps

講演要旨：

Interactions between deterministic chaos and stochastic randomness have been an
important problem in nonlinear dynamical systems studies. Noise-induced phenomena 
are understood as a drastic change of natural invariant densities by adding external noise 
to a deterministic dynamics, resulting qualitative transition of observed nonlinear phenomena. 
Stochastic resonance, noise-induced synchronization, and noise-induced chaos are typical examples. 
The simplest mathematical model is given as one-dimensional maps perturbed by stochastic noise.  
　In this presentation, we discuss typical behavior of noised dynamical systems based on 
numerically observed noise-induced phenomena in one-dimensional maps. Our observation 
indicates that (i) both noise-induced chaos and noise-induced order may coexist, and 
that (ii) asymptotical periodicity of densities bifurcates according to noise amplitude. 
A brief overview of nonlinear phenomena in random dynamical systems are also discussed 
with exemplifying an application for extracting random dynamics from a time-series.