Gauge invariant renormalizability of quantum gravity

Understand

Using the Batalin-Vilkovisky technique and the background field method the proof of gauge invariant renormalizability is elaborated for a generic model of quantum gravity which is diffeomorphism invariant and has no other, potentially anomalous, symmetries.

• The gauge invariant renormalizability means that in all orders of loop expansion of the quantum effective action one can control deformations of the generators of gauge transformations which leave such an action invariant.
• In quantum gravity this means that one can maintain general covariance of the divergent part of effective action when the mean quantum field, ghosts and antifields are switched off.