Discrete double-porosity models for spin systems

We consider spin systems between a finite number N of "species" or "phases" partitioning a cubic lattice Zd. We suppose that interactions between points of the same phase are coercive while those between points of different phases (or possibly between points of an additional "weak phase") are of lower order. Following a discrete-to-continuum approach, we characterize the limit as a continuum energy defined on N-tuples of sets (corresponding to the N strong phases) composed of a surface part, taking into account homogenization at the interface of each strong phase, and a bulk part that describes the combined effect of lowerorder terms, weak interactions between phases, and possible oscillations in the weak phase.