The Post-Newtonian Limit of Dilaton Gravity

TL;DR

This paper analyzes the post-Newtonian limit of a generalized dilaton gravity theory, deriving field equations and solutions for a charged point mass, highlighting the detectability of dilaton effects with charged test particles.

Contribution

It provides the first detailed post-Newtonian analysis of dilaton gravity coupled with electromagnetic fields, including solutions for charged masses and consistency checks with black hole solutions.

Findings

Dilaton effects are detectable with charged test particles at the post-Newtonian level.

Derived approximate solutions for a charged point mass in dilaton gravity.

Confirmed consistency with weak field expansions of charged dilaton black holes.

Abstract

We study the post-Newtonian limit of a generalized dilaton gravity in which gravity is coupled to dilaton and eletromagnetic fields. The field equations are derived using the post-Newtonian scheme, and the approximate solution is presented for a point mass with electric and dilaton charges. The result indicates that the dilaton effect can be detected, in post-Newtonian level, using a charged test particle but not a neutral one. We have also checked that the approximate solution is indeed consistent with the weak field expansion of charged dilaton black hole solution in the harmonic coordinate.