RT Journal Article T1 Conformal and non conformal dilaton gravity A1 Álvarez, Enrique A1 Herrero Valea, Mario A1 Martin, C. P. AB The quantum dynamics of the gravitational field non-minimally coupled to an (also dynamical) scalar field is studied in the broken phase. For a particular value of the coupling the system is classically conformal, and can actually be understood as the group averaging of Einstein-Hilbert’s action under conformal transformations. Conformal invariance implies a simple Ward identity asserting that the trace of the equation of motion for the graviton is the equation of motion of the scalar field. We perform an explicit one-loop computation to show that the DeWitt effective action is not UV divergent on shell and to find that the Weyl symmetry Ward identity is preserved on shell at that level. We also discuss the fate of this Ward identity at the two-loop level — under the assumption that the two-loop UV divergent part of the effective action can be retrieved from the Goroff-Sagnotti counterterm — and show that its preservation in the renormalized theory requires the introduction of counterterms which exhibit a logarithmic dependence on the dilaton field. PB Springer SN 1029-8479 YR 2014 FD 2014-10-21 LK https://hdl.handle.net/20.500.14352/34572 UL https://hdl.handle.net/20.500.14352/34572 LA eng NO SCOAP3 DS Docta Complutense RD 8 may 2024