Regular wave propagation out of noise in chemical active media - art. no. 078302

A pacemaker, regularly emitting chemical waves, is created out of noise whe n an excitable photosensitive Belousov-Zhabotinsky medium, strictly unable to autonomously initiate autowaves, is forced with a spatiotemporal pattern ed random illumination. These experimental observations are also reproduced numerically by using a set of reaction-diffusion equations for an activato r-inhibitor model, and further analytically interpreted in terms of genuine coupling effects arising from parametric fluctuations. Within the same fra mework we also address situations of noise-sustained propagation in subexci table media.