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arXiv · 1506.04977

Scalar instabilities in bimetric gravity: The Vainshtein mechanism and structure formation

Edvard Mortsell·Jonas Enander
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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.

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Edvard Mortsell, Jonas Enander. 2015-07-06. Scalar instabilities in bimetric gravity: The Vainshtein mechanism and structure formation. https://doi.org/10.1088/1475-7516%2F2015%2F10%2F044

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