A FOUR-VARIABLE CHAOTIC CHEMICAL REACTION

A four-variable reaction system, consisting of a three variable chaos producing subsystem and a weakly coupled fourth variable, is presented. Considering the slow fourth variable as a parameter, the amplitude of the three-variable chaotic subsystem abruptly changes from a small to a large value without hysteresis. The fourth variable is made dependent on the mean value of this amplitude, so that a superimposed slow oscillation results. A Poincare cross section and a set of Lyapunov characteristic exponents are presented. The question of the dimensionality of the attractor is discussed.