Generalized Gauge Transformations and Regularized $\lambda\phi^4$-type   Abelian Vertices
  Abelian Lagrangians containing Phi^4-type vertices are regularized by means of a suitable point-splitting scheme combined with generalized gauge transformations.. The calculation is developed in details for a general Lagrangean, whose fields (gauge and matter ones) satisfy usual conditions. We illustrate our results by considering some special cases, such as the ($\overline{\psi}\psi)^2 and a modified version of the Avddev-Chizhov models. Possible application of our results to the Abelian Higgs model, whenever spontaneous symmetry breaking is considered, is also discussed. We also pay attention to a number of features of the point-split action such as the regularity and non-locality of its new ``interacting terms''. 
Winder A. Moura-Melo and J.A. Helayel-Neto