Photon propagation function: spectral analysis of its asymptotic form.
The physical attitudes of source theory, displacing those of renormalized, perturbative, operator field theory, are used in a simple discussion of the asymptotic behavior of the photon propagation function. A guiding principle is the elementary consistency requirement that, under circumstances where a physical parameter cannot be accurately measured, no sensitivity to its precise value can enter the description of those circumstances. The mathematical tool is the spectral representation of the propagation function, supplemented by an equivalent phase representation. The Gell-Mann-Low equation is recovered, but with their function now interpreted physically as the spectral weight function. A crude inequality is established for the latter, which helps in interpolating between the initial rising behavior and the ultimate zero at infinite mass. There is a brief discussion of the aggressive source theory viewpoint that denies the existence of a "bare charge".
Schwinger
J
J
University of California, Los Angeles, Calif. 90024.