Post-Newtonian parameters and cosmological constant of screened modified gravity
Abstract
Screened modified gravity (SMG) is a kind of scalar-tensor theory with screening mechanisms, which can generate a screening effect to suppress the fifth force in high density environments and pass the solar system tests. Meanwhile, the potential of the scalar field in the theories can drive the acceleration of the late Universe. In this paper, we calculate the parametrized post-Newtonian (PPN) parameters γ and β , the effective gravitational constant Geff, and the effective cosmological constant Λ 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 formulas 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.
- Publication:
-
Physical Review D
- Pub Date:
- June 2016
- DOI:
- 10.1103/PhysRevD.93.124003
- arXiv:
- arXiv:1603.09450
- Bibcode:
- 2016PhRvD..93l4003Z
- Keywords:
-
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 15 pages, 1 figure, Phys. Rev. D accepted