A note on the asymptotic expansion of Feynman amplitudes (Q1091496)

Employing a technique introduced by \textit{M. C. Bergère} and \textit{Y.-M. P. Lam} [Commun. Math. Phys. 39, 1-32 (1974)] the authors determine the asymptotic expansion of the Feynman amplitude (in the integral representation of Schwinger) when the masses of any subset of internal lines tend to zero. They use a ``desingularization procedure'' which is analogous to one introduced by \textit{E. R. Speer} [Ann. Inst. Henri Poincaré 26, 87-105 (1977)].