Dynamical 4-D Gauss-Bonnet action from matter-graviton interaction at one-loop

The occurrence of singularities at the centers of black holes suggests that general relativity (GR), although a highly successful model of gravity and cosmology, is inapplicable. This is due to the breakdown of the equivalence principle. Gauss-Bonnet (GB) action is a simplest extension of GR as it possess second-order equations of motion and is devoid of ghosts. However, in 4-D, the GB action is topological. Recently, Glavan and Lin proposed a mathematical framework that transforms the 4-D GB gravity theory into a non-topological one. However, it has been argued that without a canonical way to choose 4-D from the higher-dimensional space, such a GB gravity is not well-defined in 4-D. The current work takes a step in addressing this issue by demonstrating that the rescaling of the GB coupling α → α/(D - 4) arises from the self-energy correction of gravitons in 4-D via the dimensional regularization. To keep things transparent, we focus on the linearized theory of gravity coupled with matter fields. By computing the one-loop self-energy correction of gravitons induced by the matter fields, we explicitly provide the origin of the prescription provided by Glavan and Lin. Our work naturally opens a new window to considering 4-D Einstein Gauss-Bonnet gravity as the most straightforward modification to GR.