A general theory of linear cosmological perturbations: bimetric theories

Journal article

We implement the method developed in [1] to construct the most general parametrised action for linear cosmological perturbations of bimetric theories of gravity. Specifically, we consider perturbations around a homogeneous and isotropic background, and identify the complete form of the action invariant under diffeomorphism transformations, as well as the number of free parameters characterising this cosmological class of theories. We discuss, in detail, the case without derivative interactions, and compare our results with those found in massive bigravity.

Authors: Lagos, M; Ferreira, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Institute of Physics
• Journal: Journal of Cosmology and Astroparticle Physics
• Volume: 2017
• Issue: 01
• Pages: 047
• Publication date: 2017-01-01
• Acceptance date: 2017-01-11
• DOI: 10.1088/1475-7516/2017/01/047
• EISSN: 1475-7516
• Keywords: Cosmology; cosmological perturbation theory; gravity; perturbations; parametrisation; bigravity; modified gravity