On the cutoff identification and the quantum improvement in asymptotic safe gravity

Research paper by R. Moti, A. Shojai

Indexed on: 21 Dec '18Published on: 21 Dec '18Published in: arXiv - General Relativity and Quantum Cosmology


The truncation method of Reuter to search for non-Gaussian fixed points of gravitational coupling which saves the theory from UV divergences, is followed by two steps: cutoff identification and improvement. Although there are various models for identifying the cutoff momentum by some physical length, none of them saves the general covariance of the action. Hence, the improvement is usually done at the level of the equations of motion. In this paper, using an arbitrary function of curvature invariants for cutoff identification is suggested. It is shown that the field equations for this approach differs from the ones obtained from the conventional cutoff identification and improvement, even for non-vacuum solutions of the improved Einstein equations. Indeed, it is concluded that these two steps are correlated to each other.