BOSONIZATION OF LATTICE FERMIONS

For any purely fermionic system on a lattice in arbitrary space dimens ion we prove that there is a different but well-defined system on the same lattice, consisting of both bona fide fermions and bosons with an interaction depending on a parameter lambda, which characterizes a sa me-site repulsion between particles. The energy spectrum and the scatt ering matrix of the former are identical to those in the finite energy sector of the latter, in the limit lambda --> infinity (i.e., hard-co re repulsion). This general theorem is applied to a resonance-boson mo del in a lattice fermion system, whose solution may have relevance to high-T(c) superconductivity.