Fixed Poles in Virtual Compton Amplitudes

Abstract

It is suggested that the leading fixed-pole terms in virtual Compton amplitudes are polynomial functions of the photon mass variable $q^2$.. Several arguments are given in support of this conjecture. Implications of this behavior in the calculation of the electromagnetic mass differences and in the $q^2$ dependence of the $e-p$ inelastic-scattering structure functions are discussed.