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arXiv · 1205.3167

Screening Modifications of Gravity through Disformally Coupled Fields

Tomi S. Koivisto·David F. Mota·Miguel Zumalacarregui
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Abstract

It is shown that extensions to General Relativity, which introduce a strongly coupled scalar field, can be viable if the interaction has a non-conformal form. Such disformal coupling depends upon the gradients of the scalar field. Thus, if the field is locally static and smooth, the coupling becomes invisible in the solar system: this is the disformal screening mechanism. A cosmological model is considered where the disformal coupling triggers the onset of accelerated expansion after a scaling matter era, giving a good fit to a wide range of observational data. Moreover, the interaction leaves signatures in the formation of large-scale structure that can be used to probe such couplings.

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Tomi S. Koivisto, David F. Mota, Miguel Zumalacarregui. 2012-11-07. Screening Modifications of Gravity through Disformally Coupled Fields. https://doi.org/10.1103/physrevlett.109.241102

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