Spectral mass sum rules for interacting fermi fields

Summary

Spectral representations and recursive equations among Schwinger functions are exploited to obtain nonperturbative relations—spectral mass sum rules—involving mean values of spectral masses and physical parameters of the theory in interacting Fermi fields models. For the Yukawa model in two space-time dimensions, the finite part of the mass sum rule is extracted, and upper bounds (mean-field-like) on the average spectral mass and on the physical mass are obtained.