Dynamics and pattern formation in an oscillatory reaction -diffusion system

We have made a detailed study of the spatial and temporal dynamics present in a forced oscillatory reaction diffusion system. Our experiments are carried out using a light-sensitive Belousov-Zhabotinsky chemical reaction and a particular chemical reactor that allows us to study the reaction in two dimensions. A periodic external driving force is provided by a commercial video projector using the light sensitivity of the chemical reaction. The driving force is parametrized by its period and the intensity of the light. We are interested in the case when the chemical oscillations become entrained to the periodic forcing. In general this is in the form of frequency locking, also called resonance, where the response frequency (n) is a rational fraction (m:n) of the forcing frequency (m).;We present the mechanisms in terms of the relationship between the spatial states and temporal dynamics for a variety of pattern forming regimes in the 2:1 resonance. In the 3:1 resonance regime we study a period doubling transition as the light intensity is increased. In the 4:1 resonance regime we study how the results of the 2:1 regime are affected by the change in symmetry between the 2:1 and 4:1 responses. Lastly, we present results when the oscillator system is subject to spatially inhomogeneous conditions.;Where possible we have compared our experimental results with published theory either analytic or numeric. In the cases where no theory exists we have done our best to present a numerical simulation, give an analytic explanation for our observations, or present an ansatz solution to a theoretical model.;We have, in general, studied two aspects of a spatially extended far from equilibrium oscillatory system subject to an external driving force: the stable spatial states and the temporal dynamics. We have found that in many cases these two ideas must be understood simultaneously and it is the goal of this thesis to demonstrate this result.