https://doi.org/10.1140/epjc/s10052-015-3441-6
Regular Article - Theoretical Physics
Inflationary cosmology from quantum conformal gravity
1
FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Praha 1, Czech Republic
2
ITP, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
3
Department of Mathematics, College of Engineering, American University of the Middle East, P.O. Box 220, 15453, Dasman, Kuwait
4
Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
* e-mail: fabio@phys.ntu.edu.tw
Received:
6
February
2015
Accepted:
5
May
2015
Published online:
3
June
2015
We analyze the functional integral for quantum conformal gravity and show that, with the help of a Hubbard–Stratonovich transformation, the action can be broken into a local quadratic-curvature theory coupled to a scalar field. A one-loop effective-action calculation reveals that strong fluctuations of the metric field are capable of spontaneously generating a dimensionally transmuted parameter which, in the weak-field sector of the broken phase, induces a Starobinsky-type f(R)-model with a gravi-cosmological constant. A resulting non-trivial relation between Starobinsky’s parameter and the gravi-cosmological constant is highlighted and implications for cosmic inflation are briefly discussed and compared with the recent PLANCK and BICEP2 data.
© The Author(s), 2015
