Renormalization group flow of quantum gravity in the EinsteinHilbert truncation
Abstract
The exact renormalization group equation for pure quantum gravity is used to derive the nonperturbative <ib>β</ib>functions for the dimensionless Newton constant and cosmological constant on the theory space spanned by the EinsteinHilbert truncation. The resulting coupled differential equations are evaluated for a sharp cutoff function. The features of these flow equations are compared to those found when using a smooth cutoff. The system of equations with a sharp cutoff is then solved numerically, deriving the complete renormalization group flow of the EinsteinHilbert truncation in d=4. The resulting renormalization group trajectories are classified and their physical relevance is discussed. The nontrivial fixed point which, if present in the exact theory, might render quantum Einstein gravity nonperturbatively renormalizable is investigated for various spacetime dimensionalities.
 Publication:

Physical Review D
 Pub Date:
 March 2002
 DOI:
 10.1103/PhysRevD.65.065016
 arXiv:
 arXiv:hepth/0110054
 Bibcode:
 2002PhRvD..65f5016R
 Keywords:

 11.10.Hi;
 04.60.m;
 11.10.Jj;
 11.15.Tk;
 Renormalization group evolution of parameters;
 Quantum gravity;
 Asymptotic problems and properties;
 Other nonperturbative techniques;
 High Energy Physics  Theory;
 General Relativity and Quantum Cosmology
 EPrint:
 58 pages, latex, 24 figures