Known results on two-dimensional quantum electrodynamics (QED_2) have been
used to study the dependence of functional renormalization group equations on
renormalization schemes and approximations applied for its bosonized version.
It is demonstrated that the singularity of flow equations can be avoided in the
optimized and power-law schemes for the bosonized model and the drawback of
renormalization on bosonization is shown: it is indicated that renormalization
of QED_2 possibly requires interaction terms corresponding to higher frequency
modes of its bosonized version.Comment: v3: 8 pages, 7 figures, final version, published in Phys. Rev.
