Observations of a torus in a model of the Belousov-Zhabotinskii reaction

The first observation of quasiperiodic oscillations in a model of the Belousov–Zhabotinskii reaction is presented and the evolution along two parameter paths of the associated torus is described. Comparison is made with experiment and the hysteresis–Hopf normal form. The model dynamics is shown to be more complex than that of the normal form. The torus is also shown to be related to two other features of the BZ reaction: (1) the transition from small amplitude to mixed-mode oscillations and (2) alternating periodic–chaotic sequences.