The Thirring Model and various generalizations of it are analyzed in d
etail. The four-fermi interaction modifies the equation of state. Chem
ical potentials and twisted boundary conditions both result in complex
fermionic determinants which are computed. The nonminimal coupling to
gravity leads to a deformation of the conformal algebra which in part
icular contains the minimal models. We compute the central charges, co
nformal weights and finite size effects. For the gauged model we deriv
e the partition functions and the explicit expression for the chiral c
ondensate at finite temperature and curvature. The Bosonization in com
pact curved space-times is also explained. (C) 1996 Academic Press, In
c.