Conformal metric-affine gravities. Issue 10 (1st October 2022)

• Record Type: Journal Article
• Authors: Olmo, Gonzalo J.; Orazi, Emanuele; Pradisi, Gianfranco
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2022:Issue 10(2022)
• Publication Date: 2022-10-01
• Subjects: Gauss-Bonnet-Lovelock-Horndeski-Palatini etc gravity theories -- modified gravity; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2022/10/057
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: We revisit the gauge symmetry related to integrable projective transformations in metric-affine formalism, identifying the gauge field of the Weyl (conformal) symmetry as a dynamical component of the affine connection. In particular, we show how to include the local scaling symmetry as a gauge symmetry of a large class of geometric gravity theories, introducing a compensator dilaton field that naturally gives rise to a Stückelberg sector where a spontaneous breaking mechanism of the conformal symmetry is at work to generate a mass scale for the gauge field. For Ricci-based gravities that include, among others, General Relativity, f ( R ) and f ( R, R μν R μν ) theories and the EiBI model, we prove that the on-shell gauge vector associated to the scaling symmetry can be identified with the torsion vector, thus recovering and generalizing conformal invariant theories in the Riemann-Cartan formalism, already present in the literature.