A phenomenological operator description of interactions between populations with applications to migration

We adopt an operatorial method based on the so–called creation, annihilation and number operators in the description of different systems in which two populations interact and move in a two–dimensional region. In particular, we discuss diffusion processes modeled by a quadratic hamiltonian. This general procedure will be adopted, in particular, in the description of migration phenomena. With respect to our previous analogous results, we use here fermionic operators since they automatically implement an upper bound for the population densities.