HIGHER-DERIVATIVE 4-FERMION MODEL IN CURVED SPACETIME

We discuss the phase structure of a higher derivative four-fermion mod el in four dimensions in curved spacetime in frames of the 1/N-c-expan sion. First, we evaluate in our model the effective potential of two c omposite scalars in the linear curvature approximation using a local m omentum representation in curved spacetime for the higher-derivative p ropagator which naturally appears. The symmetry breaking phenomenon an d phase transition induced by curvature are numerically investigated. A numerical study of the dynamically generated fermionic mass, which d epends on the coupling constants and on the curvature, is also present ed.