Localization and averaged Green's functions

We present a counterexample to the idea that localization in a random material can be determined from the ensemble averaged Green's function.     

SMJ's analysis of Ising model correlation functions

In a series of recent publications Sato, Miwa, and Jimbo (SMJ) have shown how to derive multispin correlation functions of the two-dimensional Ising model in the continuum, or scaling, limit by analyzing the behavior of the solutions to the two-dimensional version of the Dirac equation. The major purpose of the present work is to describe SMJ's analysis more discursively and in terms closer to that used in previous studies of the Ising model. In addition, new and more compact expressions for their basic equations are derived. A single new answer is obtained: the form of the three-spin correlation function at criticality.     

On the infrared singularities of Green's functions in quantum electrodynamics

We present a formal calculation of the infrared singularity structure of the fermion propagator in QED based on the Faddeev-Kulish asymptotic solution. The Renormalization program is reviewed in the context of the BPHZ subtraction scheme and a refinement of the Renormalization group methods is employed to study the infrared singularities in perturbation theory.     

A relation between Holstein's photon escape transmission factor and the equivalent width

It is shown that the photon escape transmission factor for a spectrum line in a homogeneous gas, defined by Holstein in his study of the imprisonment of resonance radiation, is a useful derivative of the equivalent width or total absorption of the line.