  In equilibrium systems with short-ranged interactions, the relative stability
of different thermodynamic states generally does not depend on system size (as
long as this size is larger than the interaction range). Here, we use a large
deviations approach to show that, in contrast, different states can exchange
stability as system size is varied in a driven, bistable reaction-diffusion
system. This striking effect is related to a shift from a spatially uniform to
a nonuniform transition state and should generically be possible in a wide
range of nonequilibrium physical and biological systems.
