Unified post-Newtonian analysis reveals that Palatini scalar-tensor theories often face weaker Solar System bounds than metric versions due to stronger Yukawa suppression, with Palatini f(R) reproducing GR limits for point sources unlike metric f(R).
Post-Newtonian parameters and cosmological constant of screened modified gravity
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Screened modified gravity (SMG) is a kind of scalar-tensor theories with screening mechanisms, which can generate screening effect to suppress the fifth force in high density environments and pass the solar system tests. Meanwhile, the potential of scalar field in the theories can drive the acceleration of the late universe. In this paper, we calculate the parameterized post-Newtonian (PPN) parameters $\gamma$ and $\beta$, the effective gravitational constant $G_{\rm eff}$ and the effective cosmological constant $\Lambda$ for SMG with a general potential $V$ and coupling function $A$. The dependence of these parameters on the model parameters of SMG and/or the physical properties of the source object are clearly presented. As an application of these results, we focus on three specific theories of SMG (chameleon, symmetron and dilaton models). Using the formulae to calculate their PPN parameters and cosmological constant, we derive the constraints on the model parameters by combining the observations on solar system and cosmological scales.
citation-role summary
citation-polarity summary
fields
gr-qc 2verdicts
UNVERDICTED 2roles
background 1polarities
background 1representative citing papers
Combined Cassini, LLR, and pulsar observations tighten bounds on scalar-tensor gravity with and without screening, with LLR improving SMG limits by over seven orders of magnitude.
citing papers explorer
-
Post-Newtonian Constraints on Scalar-Tensor Gravity
Unified post-Newtonian analysis reveals that Palatini scalar-tensor theories often face weaker Solar System bounds than metric versions due to stronger Yukawa suppression, with Palatini f(R) reproducing GR limits for point sources unlike metric f(R).
-
Constraining the scalar-tensor gravity theories with and without screening mechanisms by combined observations
Combined Cassini, LLR, and pulsar observations tighten bounds on scalar-tensor gravity with and without screening, with LLR improving SMG limits by over seven orders of magnitude.