Post-Newtonian parameters and cosmological constant of screened modified
  gravity
  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.
