Properties Of The Classical Action Of Quantum Gravity

Understand

The classical action of quantum gravity, determined by renormalization, contains infinitely many independent couplings and can be expressed in different perturbatively equivalent ways.

• We organize it in a convenient form, which is based on invariants constructed with the Weyl tensor.
• We show that the FLRW metrics are exact solutions of the field equations in arbitrary dimensions, and so are all locally conformally flat solutions of the Einstein equations.
• Moreover, expanding the metric tensor around locally conformally flat backgrounds the quadratic part of the action is free of higher derivatives.