We are interested  (a) in dynamical mass generation 
(chiral symmetry breaking) at finite temperature using Schwinger-
Dyson equations,and in the associated phase structure; and (b) in 
the infrared behaviour of the theory (particularly critical 
exponents) in the chirally symmetric phase. Papers include
I.J.R.Aitchison, Z.Phys. C 67, 303 (1995), I.J.R.Aitchison, D.McNeill 
and N.E.Mavromatos, Phys.Lett. B 402, 154 (1997).One possible 
application is to the planar cuprate superconductors : in this case, 
the U(1) gauge field is associated with the spin interaction, and a 
second U(1) represents electromagnetism (see N.Dorey and N.E.Mavromatos, 
Nucl.Phys. B 386, 614 (1992)). This simple model may explain some of the 
unusual features of both the normal and the superconducting phases of these 
materials ( I.J.R.Aitchison and N.E.Mavromatos, Phys.Rev. B 53, 9321 (1996)).