MIXED BOSON-FERMION DESCRIPTION OF CORRELATED ELECTRONS - FLUCTUATIONCORRECTIONS IN THE SYMMETRICAL TREATMENT

We consider the introduction of fluctuation corrections to saddle-poin t results in the symmetric treatment of a mixed pseudofermion-boson re presentation of correlated electrons. In our calculations we avoid the complications of working in the discrete imaginary-time formulation o f the functional integral, a procedure recently advocated in the liter ature as mandatory for this problem. For a simple two-site model our a pproach leads to approximate results in remarkable agreement with the exact results, and without the spurious nonanalyticities of other simi lar treatments.