2014/02/19 by Yousef Bisabr
Physics and Astronomy · #gr-qc
paper · pdf · doi:10.1007/s10509-013-1751-4
published as Astrophys Space Sci (2014) 350:407-411 · 9 pages, no figure. To appear in Astrophysics and Space Science. arXiv admin note: text overlap with arXiv:0907.3838, arXiv:1005.5670, arXiv:1212.2709
arxiv created 2014/02/19 · arxiv updated 2015/06/18
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.