AMBIGUITIES IN THE THIRRING MODEL UNDER CHIRAL ROTATIONS

We study how different parametrizations of the Thirring model behave under finite chiral rotations with the zeta-function regularization for the fermion determinant. We show that in some cases the contribution from the chiral Jacobian may change the sign of the factor which multiplies the quadratic term in the auxiliary field leading to an exponentially divergent theory. We also propose how this problem could be remedied by exploiting the invariance of the theory under finite renormalizations.