RENORMALIZATION-GROUP STRUCTURE OF CONFORMAL QUANTUM-GRAVITY WITH MATTER NEAR 4 DIMENSIONS

The phase structure and infrared (IR) properties of conformal quantum gravity (QG) with matter near four dimensions are studied using renorm alization-group (RG) and epsilon-expansion techniques. For a variety o f theories [like the O(N) phi(4) theory, scalar electrodynamics and th e SU(2) model with scalars] interacting with Weyl gravity, new fixed p oints for the scalar coupling may appear. The IR stable fixed point pe rturbed by QG results in a second-order phase transition at nonzero te mperature. For the SU(2) gauge theory, which presumably describes the confining phase of the standard model, the RG-improved effective poten tial at nonzero temperature is found taking into account the QG contri bution.