Quantum cosmology and stationary states

Abstract

A model for quantum gravity, in which the conformal part of the metric is quantized using the path integral formalism, is presented. Einstein's equations can be suitably modified to take into account the effects of quantum conformal fluctuations. A closed Friedman model can be described in terms of well-defined stationary states. The "ground states" sets a lower bound (at Plank length) to the scale factor preventing the collapse. A possible explanation for matter creation and quantum nature of matter is suggested.