NEW RESULTS ON GAMMA(STR) IN 2D QUANTUM-GRAVITY USING REGGE CALCULUS

We study 2D quantum gravity on spherical topologies using the Regge ca lculus approach. Our goal is to shed new light upon the validity of th e Regge approach to quantum gravity, which has recently been questione d in the literature. We incorporate an R(2) interaction term and inves tigate its effect on the value of the string susceptibility exponent g amma(str) using two different finite-size scaling Ansatze. Our results suggest severe shortcomings of the methods used so far to determine g amma(str) and show a possible cure of the problems. To have better con trol over the influence of irregular vertices, we choose besides the a lmost regular triangulation of the sphere as the surface of a cube a r andom triangulation according to the Voronoi-Delaunay prescription.