Renormalization group equation for f (R ) gravity on hyperbolic spaces
Abstract
We derive the flow equation for the gravitational effective average action in an f (R ) truncation on hyperbolic spacetimes using the exponential parametrization of the metric. In contrast to previous works on compact spaces, we are able to evaluate traces exactly using the optimized cutoff. This reveals in particular that all modes can be integrated out for a finite value of the cutoff due to a gap in the spectrum of the Laplacian, leading to the effective action. Studying polynomial solutions, we find poorer convergence than has been found on compact spacetimes even though at small curvature the equations only differ in the treatment of certain modes. In the vicinity of an asymptotically free fixed point, we find the universal beta function for the R2 coupling and compute the corresponding effective action which involves an R2log (R2) quantum correction.
- Publication:
-
Physical Review D
- Pub Date:
- October 2016
- DOI:
- 10.1103/PhysRevD.94.084005
- arXiv:
- arXiv:1607.08460
- Bibcode:
- 2016PhRvD..94h4005F
- Keywords:
-
- High Energy Physics - Theory;
- General Relativity and Quantum Cosmology
- E-Print:
- 31 pages, 5 figures. Version to be published in Phys. Rev. D