Post-Newtonian parameter γ in generalized non-local gravity

We investigate the post-Newtonian parameter 7 and derive its formalism in generalized non-local （GNL） gravity, which is the modified theory of general relativity （GR） obtained by adding a term m2n-2 R -nR to the Einstein-Hilbert action. Concretely, based on parametrizing the generalized non-local action in which gravity is described by a series of dynamical scalar fields ~i in addition to the metric tensor g μ v, the post-Newtonian limit is computed, and the effective gravitational constant as well as the post-Newtonian parameters are directly obtained from the generalized non-local gravity. Moreover, by discussing the values of the parametrized post-Newtonian parameters 9,, we can compare our expressions and results with those in Hohmann and Jarv et al. （2016）, as well as current observational constraints on the values of γ in Will （2006）. Hence, we draw restrictions on the nonminimal coupling terms F- around their background values.

We investigate the post-Newtonian parameter γ and derive its formalism in generalized non-local(GNL) gravity, which is the modified theory of general relativity(GR) obtained by adding a term m^(2n-2)R□(-n)R to the Einstein-Hilbert action. Concretely,based on parametrizing the generalized non-local action in which gravity is described by a series of dynamical scalar fields φ~i in addition to the metric tensor g_(μν), the post-Newtonian limit is computed, and the effective gravitational constant as well as the post-Newtonian parameters are directly obtained from the generalized non-local gravity. Moreover, by discussing the values of the parametrized post-Newtonian parameters γ, we can compare our expressions and results with those in Hohmann and Jrv et al.(2016), as well as current observational constraints on the values of γ in Will(2006). Hence, we draw restrictions on the nonminimal coupling terms F around their background values.