Does the Light Cone Dominate the Asymptotic Behavior of Vertex Functions and Scattering Amplitudes?

Abstract

The hypothesis of leading light-cone singularity dominance is examined for vertex functions in the so-called $A$ limit with $\omega =1\mathrm{}$ and for scattering amplitudes in the Regge limit. It is shown that, in the field expansion, terms less singular on the light cone must be as important asymptotically as the more singular terms, unless the asymptotic behavior changes abruptly when an external leg goes slightly off the mass shell.