Gravitational phase transitions in infrared quantum gravity

The conformal anomaly induced sector of four-dimensional quantum gravity (infrared quantum gravity) —which has been introduced by Antoniadis and Mottola— is here studied on a curved fiducial background. The one-loop effective potential for the effective conformal factor theory is calculated with accuracy, including terms linear in the curvature. It is proven that a curvature induced phase transition can actually take place. An estimation of the critical curvature for different choices of the parameters of the theory is given. E-mail address: eli @ ebubecm1.bitnet On sabbatical leave from Tomsk Pedagogical Institute, 634041 Tomsk, Russia. E-mail address: odintsov @ theo.phys.sci.hiroshima-u.ac.jp