Wave propagation in subexcitable media with periodically modulated excitability

Wave propagation in a photosensitive, subexcitable Belousov-Zhabotinsky med ium is made possible by periodic modulation of a homogeneous illumination h eld. The propagation can be understood in terms of an interplay between the radial expansion of the wave and the motion of its free ends as the excita bility varies periodically. This description leads to a simple kinematic an alysis that provides insights into the initial conditions and forcing param eters giving rise to sustained wave propagation.