Effective theory for quantum gravity

Abstract

In this paper, we discuss an effective theory for quantum gravity and discuss the bounds on the parameters of this effective action. In particular we show that measurement in pulsars binary systems are unlikely to improve the bounds on the coefficients of the $R^2$ and $R_{\mu\nu} R^{\mu\nu}$ terms obtained from probes of Newton's potential performed on Earth. Furthermore, we argue that if the coefficients of these terms are induced by quantum gravity, they should be at most of order unity since $R^2$ and $R_{\mu\nu} R^{\mu\nu}$ are dimension four operators. The same applies to the non-minimal coupling of the Higgs boson to the Ricci scalar.