2-COMPONENT SPREADING PHENOMENA - WHY THE GEOMETRY MAKES THE CRITICALITY

We have numerically and theoretically investigated a simple model for two-component spreading phenomena in two different growth geometries ( i.e., spreading confined in a half space and spreading in a free space ). The criticality of the domain substructures unexpectedly depends on the considered geometry. This is understood by simple arguments of do main-wall particle diffusion and annihilation. We derive a relationshi p between the critical exponents chi and alpha for domain-wall spatial distributions in different geometries. The latter relationship is num erically verified in two, three, and four dimensions.