2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185566The Schwinger-Dyson equation of fermion self-energy in the linearization approximation is solved exactly in a theory with gauge and effective four-fermion interactions. Different expressions for the indepedent solutions which respectively submit to irregular and regular ultraviolet boundary condition are derived and expounded.12 pages, Latex, no figuesHigh Energy Physics - Theorytext