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arXiv · 1402.4779

Notes on the Chameleon Brans-Dicke Gravity

Yousef Bisabr
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Abstract

We consider a generalized Brans-Dicke model in which the scalar field has a potential function and is also allowed to couple non-minimally with the matter sector. This anomalous gravitational coupling can in principle avoid the model to pass local gravity experiments. One then usually assumes that the scalar field has a chameleon behavior in the sense that it acquires a density-dependent effective mass. While it can take a small effective mass in cosmological (low-density environment) scale, it has a sufficiently heavy mass in Solar System (large-density environment) and then hides gravity tests. We will argue that such a chameleon behavior can not be generally realized and depends significantly on the forms attributed to the potential and the coupling functions.

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Yousef Bisabr. 2014-02-19. Notes on the Chameleon Brans-Dicke Gravity. https://doi.org/10.1007/s10509-013-1751-4

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