YUKAWA MODEL IN CURVED SPACETIME

The Yukawa model in curved spacetime (renormalizable in the usual sens e) is considered near the critical point, using the 1/N-expansion and renormalization group techniques. The equivalence of this model with t he standard NJL model is proven. The behavior of the graviton-scalar b ound state coupling constant near the ir stable fixed point xi = 1/6 i s discussed. The effective potential is calculated and a dynamically g enerated fermionic mass is found. Some applications to quantum gravity which make explicit use of the 1/N-expansion are briefly discussed. I n particular, a possible solution of the cosmological constant problem within the framework of conformal factor dynamics is pointed out.