Cosmology of Extended Proca-Nuevo. Issue 3 (1st March 2022)

• Record Type: Journal Article
• Authors: de Rham, Claudia; Garcia-Saenz, Sebastian; Heisenberg, Lavinia; Pozsgay, Victor
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2022:Issue 3(2022)
• Publication Date: 2022-03-01
• Subjects: dark energy theory -- Cosmological perturbation theory in GR and beyond -- modified gravity -- Gravitational waves in GR and beyond: theory; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2022/03/053
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: Proca-Nuevo is a non-linear theory of a massive spin-1 field which enjoys a non-linearly realized constraint that distinguishes it among other generalized vector models. We show that the theory may be extended by the addition of operators of the Generalized Proca class without spoiling the primary constraint that is necessary for consistency, allowing to interpolate between Generalized Proca operators and Proca-Nuevo ones. The constraint is maintained on flat spacetime and on any fixed curved background. Upon mixing extended Proca-Nuevo dynamically with gravity, we show that the constraint gets broken in a Planck scale suppressed way. We further prove that the theory may be covariantized in models that allow for consistent and ghost-free cosmological solutions. We study the models in the presence of perfect fluid matter, and show that they describe the correct number of dynamical variables and derive their dispersion relations and stability criteria. We also exhibit, in a specific set-up, explicit hot Big Bang solutions featuring a late-time self-accelerating epoch, and which are such that all the stability and subluminality conditions are satisfied and where gravitational waves behave precisely as in General Relativity.