The Master Ward Identity for Scalar QED

The Master Ward Identity andGeneralized

Ward - Takahashi Identity with External Field in Ladder QED ∗

We derive theWard-Takahashi identity obeyed by the fermion-antifermiongauge boson vertex in ladder QED in the presence of a constant magnetic field. The general structure in momentum space of the fermion mass operator with external electromagnetic field is discussed. Using it we find the solutions of the ladder WT identity with magnetic field. The consistency of our results with the solutions o...

Ward identity and electrical conductivity in hot QED

We study the Ward identity for the effective photon-electron vertex summing the ladder diagrams contributing to the electrical conductivity in hot QED at leading logarithmic order. It is shown that the Ward identity requires the inclusion of a new diagram in the integral equation for the vertex that has not been considered before. The real part of this diagram is subleading and therefore the fi...

A solution to Ward - Takahasi - identity in QED

Using spectral function of photon we find the reliable results for the effects of vacuum polarization for the dressed fermion propagator in three-dimensional QED.

A solution to Ward - Takahashi - identity in QED

Abstract We discuss the properties of fermion propagator in three dimensional QED with dressed photon based on spectral representation with LSZ reduction formula.We evaluate the spectral function by the sum of infinite numbers of rainbow type diagram for intermediate states.In this method we have the solution as one derived by renormalization group in four-dimension.Massless vacuum polarization...