Abstract:
We consider the problem of designing an Ansatz for the fermion-photon vertex function, using three-dimensional
quantum electrodynamics as a test case. In many existing studies, restrictions have been placed on
the form of the vertex Ansatz by making the unsubstantiated assumption that in the quenched, massless limit
the Landau gauge Dyson-Schwinger equations admit a trivial solution. We demonstrate, without recourse to
this assumption, the existence of a nonlocal gauge in which the fermion propagator is the bare propagator. This
result is used to provide a viable Ansatz for part of the vertex function.
