Ultraviolet Finiteness of Chiral Perturbation Theory in Two-Dimensional Quantum Electrodynamics

We consider the perturbation theory in the fermion mass (chiral perturbation theory) in the two-dimensional quantum electrodynamics. With this aim, we rewrite the theory in the equivalent bosonic form in which the interaction has the exponential form and the fermion mass becomes the coupling constant. We reformulate the bosonic perturbation theory in the superpropagator language and analyze its ultraviolet behavior. We show that the boson Green's functions without vacuum loops remain finite in all orders of the perturbation theory in the fermion mass.