Radar ranging and Doppler tracking in post-Einsteinian metric theories of gravity

TL;DR

This paper develops a formalism for radar ranging and Doppler tracking in post-Einsteinian metric theories of gravity, correcting previous results and predicting new anomalies, to evaluate if extended metrics can explain solar system observations like the Pioneer anomaly.

Contribution

It provides a complete description of electromagnetic signal delays in extended metric theories, correcting past analyses and predicting new observable anomalies.

Findings

Corrected previous Pioneer anomaly analyses

Predicted an annually modulated anomaly

Established a basis for testing extended gravity theories

Abstract

The study of post-Einsteinian metric extensions of general relativity (GR), which preserve the metric interpretation of gravity while considering metrics which may differ from that predicted by GR, is pushed one step further. We give a complete description of radar ranging and Doppler tracking in terms of the time delay affecting an electromagnetic signal travelling between the Earth and a remote probe. Results of previous publications concerning the Pioneer anomaly are corrected and an annually modulated anomaly is predicted besides the secular anomaly. Their correlation is shown to play an important role when extracting reliable information from Pioneer observations. The formalism developed here provides a basis for a quantitative analysis of the Pioneer data, in order to assess whether extended metric theories can be the appropriate description of gravity in the solar system.