Quantum corrections to unimodular gravity
Enrique Álvarez (Instituto de Física Teórica UAM/CSIC, C/Nicolas Cabrera, 13-15, C.U. Cantoblanco, Madrid, 28049, Spain, Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, 20849, Spain); Sergio González-Martín (Instituto de Física Teórica UAM/CSIC, C/Nicolas Cabrera, 13-15, C.U. Cantoblanco, Madrid, 28049, Spain, Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, 20849, Spain); Mario Herrero-Valea (Instituto de Física Teórica UAM/CSIC, C/Nicolas Cabrera, 13-15, C.U. Cantoblanco, Madrid, 28049, Spain, Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, 20849, Spain); Carmelo Martın (Universidad Complutense de Madrid (UCM), Departamento de Física Téorica I, Facultad de Ciencias Físicas, Av. Complutense S/N (Ciudad Univ.), Madrid, 28040, Spain)
The problem of the comological constant appears in a new light in Unimodular Gravity. In particular, the zero momentum piece of the potential (that is, the constant piece independent of the matter fields) does not automatically produce a cosmological constant proportional to it. The aim of this paper is to give some details on a calculation showing that quantum corrections do not renormalize the classical value of this observable.