Scalar instabilities in bimetric gravity: The Vainshtein mechanism and structure formation
Abstract
We investigate the observational consequences of scalar instabilities in bimetric theory, under the assumption that the Vainshtein mechanism restores general relativity within a certain distance from gravitational sources. We argue that early time instabilities have a negligible impact on observed structures. Assuming that the instabilities affect sub-horizon density fluctuations, we constrain the redshift, z_i, below which instabilities are ruled out. For the "minimal" beta_1-model, observational constraints are close to the theoretical expectations of z_i = 0.5, potentially allowing the model to be ruled in or out with a more detailed study, possibly including secondary cosmic microwave background constraints.
Keywords
Cite
@article{arxiv.1506.04977,
title = {Scalar instabilities in bimetric gravity: The Vainshtein mechanism and structure formation},
author = {Edvard Mortsell and Jonas Enander},
journal= {arXiv preprint arXiv:1506.04977},
year = {2015}
}
Comments
13 pages, 2 figures. v2: updated references