Gravity à la Sakharov: affine approach

Abstract: We briefly explain the idea of how gravity, as in general relativity (GR), may not be fundamental but may arise from elementary particle fields via one-loop effective actions. This old idea of Sakharov stands a priori on the metrical structure of spacetime, and the induction of the GR action. Since the former is typically considered at the heart of GR, we then argue that it might also be induced from a primary setup. To that end, we show how pure affine structure of spacetime provides a relevant framework for induced gravity where not only the scale of gravity but also the metric tensor is induced.