M ar 1 99 6 Gauged NJL model at strong curvature

We investigate the gauged NJL–model in curved spacetime using the RG formulation and the equivalency with the gauge Higgs–Yukawa model in a modified 1/N c –expansion. The strong curvature induced chiral symmetry breaking is found in the non-perturbative RG approach (presumably equivalent to the ladder Schwinger–Dyson equations). Dynamically generated fermion mass is explicitly calculated and inducing of Einstein gravity is briefly discussed. This approach shows the way to the non-perturbative study of the dynamical symmetry breaking at external fields.