Phase structure of Topologically massive gauge theory with fermion

Using Bloch-Nordsieck approximation fermion propagator in 3-dimensional gauge theory with topological mass is studied. Infrared divergence of Chern-Simon term is soft,which modifies anomalous dimension. In unquenched QCD with 2-component spinor anomalous dimension has fractional value,where order parmeter is divergent.Comment: 3 pages,Latex,no figures,for the proceedings of strong coupling gauge theory.typos corrected. anomalous dimension is corrected

Determination of the propagator in QED3 by spectral function

To study the infrared behaviour of the propagator, exponentiation of the lowest order spectral function has been known.We show this method is helpful in super renormalizable theory with dimension-full coupling constant.In the 1/N approximation anomalous dimension is independent of $N$,which plays an important role for confinement and pair condensation.Comment: 6 pages Latex,2 figures.introduction is modified.mistakes in equations are corrected.figure captions are correcte

Mass singularity and confinement

Infrared behaviour of the fermion propagator is examined by spectral representation.Assuming asymptotic states and using LSZ reduction formula we evaluate the the lowest order spectral function by definition.After exponentiation of it we derive the non perturbative propagator.It shows confinement and dynamical mass generation explicitly.Comment: 7pages,latex,prepared for light-cone 2005,typos corrected,add reference

Infrared behaviour of the fermion propagator in unquenched QED3_3 with finite threshold effects

To remove the linear infrared divergences in quenched approximation we include the massive fermion loop to the photon spectral function.Spectral function of fermion has no one particle singularity if we fix the anomalous dimension to be unity.In the case of $N$ flavour,$N$ dependence of order parameter is mild which may be due to screening effects.Comment: 12pages,6figures,Rev.tex4,typos in (13),(17),(18) are correcte