The Post-Newtonian Limit of f(R)-gravity in the Harmonic Gauge

Understand

A general analytic procedure is developed for the post-Newtonian limit of $f(R)$-gravity with metric approach in the Jordan frame by using the harmonic gauge condition.

• In a pure perturbative framework and by using the Green function method a general scheme of solutions up to $(v/c)^4$ order is shown.
• Considering the Taylor expansion of a generic function $f$ it is possible to parameterize the solutions by derivatives of $f$.
• At Newtonian order, $(v/c)^2$, all more important topics about the Gauss and Birkhoff theorem are discussed.