離散散逸系におけるカオス的パルス(<特集>パターンダイナミクス)

抄録

Existence and dynamics of chaotic pulses on 1 D lattice are discussed. Traveling pulses arise typically in reaction diffusion systems like FitzHugh-Nagumo equations. Such pulses annihilate when they collide each other. A new type of traveling pulse has been found recently in many systems where pulses bounce off like elastic balls. We consider the behavior of such a localized pattern on 1 D lattice, i. e., an infinite system of ODEs with nearest interaction of diffusive type. Besides the usual standing and traveling pulses, a new type of localized pattern, which moves chaotically on a lattice, was found numerically. Employing the strength of diffusive interaction as a bifurcation parameter, there appear two types of route from standing pulse to chaotic pulse; period-doubling and intermittent type I. If two chaotic pulses collide with an appropriate timing, it forms a periodic oscillating pulse called mollecule. Interaction among many chaotic pulses is also studied numerically.