Chayes L., Shtengel K.
Critical Behavior for 2d Uniform and
Disordered Ferromagnets at Self--Dual Points
(48K, amstex)

ABSTRACT.  We consider certain two-dimensional systems with self--dual
points including uniform and disordered $q$--state Potts
models.  For systems with continuous energy density (such as
the disordered versions) it is established that the self--dual
point exhibits critical behavior:  Infinite susceptibility,
vanishing magnetization and power law bounds for the decay of
correlations.