On the product of distributions with coincident point singularities

In this paper we generalize the result obtained by Gonzales Dominguez, Scar fiello and Fisher (A. Gonzales Dominguez and R. Scarfiello, Rev. Un. Mat. A rgentina, Volumen de Homenaje a Beppo Levi (1956) 58-67; B. Fisher, Proc. C ambridge Philos. Soc. 72 (1972) 201-204). This result can be used in quantu m field theory for the evaluation of products of propagators of the fields. With this new result we obtain the product (c(2)+P)(-n) . delta (m-1)(c(2) +P). As a physical example, we evaluate the self-energy Green function of a massless scalar field.