title: Period doubling in a periodically forced Belousov-Zhabotinsky reaction.
abstract: Using an open-flow reactor periodically perturbed with light, we observe subharmonic frequency locking of the oscillatory Belousov-Zhabotinsky chemical reaction at one-sixth the forcing frequency (6:1) over a region of the parameter space of forcing intensity and forcing frequency where the Farey sequence dictates we should observe one-third the forcing frequency (3:1). In this parameter region, the spatial pattern also changes from slowly moving traveling waves to standing waves with a smaller wavelength. Numerical simulations of the FitzHugh-Nagumo equations show qualitative agreement with the experimental observations and indicate that the oscillations in the experiment are a result of period doubling.
authors.affiliation: Center for Nonlinear and Complex Systems and Department of Physics, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Bradley
authors.initials: B
authors.lastname: Marts
authors.forename: David J W
authors.initials: DJ
authors.lastname: Simpson
authors.forename: Aric
authors.initials: A
authors.lastname: Hagberg
authors.forename: Anna L
authors.initials: AL
authors.lastname: Lin