On scale-free extensions of massive (bi-)gravity
Abstract
We discuss a scale-free model of bigravity, in which the mass parameter of the standard bigravity potential is promoted to a dynamical scalar field. This modification retains the ghost-free bigravity structure, in particular it remains free of the Boulware-Deser ghost. We investigate the theory's interaction structure, focusing on its consistent scaling limits and strong coupling scales. Furthermore we explore the model's quadratic action, both around generic background configurations and paying special attention to cosmological backgrounds and to the associated background evolution. Finally we consider the possibility of realizing a phase of late-time acceleration as well as a quasi-de Sitter inflationary stage at early times, when the promoted "mass scalar" becomes the inflaton.
Cite
@article{arxiv.1608.06643,
title = {On scale-free extensions of massive (bi-)gravity},
author = {Giulia Cusin and Nima Khosravi and Johannes Noller},
journal= {arXiv preprint arXiv:1608.06643},
year = {2017}
}
Comments
36 pages; v2 clarifying comments added, references updated, results unchanged