Cassini and extra force constraints to nonminimally coupled gravity with screening mechanism

Abstract

We consider a nonminimally coupled curvature-matter gravity theory at the Solar System scale. Both a fifth force of Yukawa type and a further non-Newtonian extra force that arises from the nonminimal coupling are present in the solar interior and in the solar atmosphere up to interplanetary space. The extra force depends on the spatial gradient of space-time curvature R. The conditions under which the effects of such forces can be screened by the chameleon mechanism and be made consistent with Cassini measurement of PPN parameter γ are examined. This consistency analysis requires a specific study of Sun's dynamical contribution to the arising forces at all its layers.

Hubble tension in a nonminimally coupled curvature-matter gravity model

“…Additionally, as discussed in ref. [45], such NMC models are not to be thought of as being composed of functions with unique powers of the curvature scalar, but as a sum of terms that would be relevant at different scales. In the example of nuclear physics given in ref.…”

“…Details on the effects of non-analytic forms of f 2 in the context of the Solar System were presented in refs. [35,45], where a screening mechanism that allows for planetary constraints to be calculated was introduced. Further discussions of the consistency of these types of inverse R dependence can be found in ref.…”