Gravity Tests with Radio Pulsars in Perturbative and Nonperturbative Regimes

TL;DR

This paper reviews how radio pulsars serve as precise tools for testing Einstein's general relativity and alternative gravity theories, especially in strong gravity regimes, through both perturbative and nonperturbative approaches.

Contribution

It highlights the role of radio pulsar timing in constraining deviations from GR and explores their potential in testing nonperturbative effects in alternative gravity theories.

Findings

Pulsar timing tightly constrains deviations from GR.

Radio pulsars are unique in probing strong gravity regimes.

Nonperturbative deviations can be tested with pulsar observations.

Abstract

Searches for empirical clues beyond Einstein's general relativity (GR) are crucial to understand gravitation and spacetime. Radio pulsars have been playing an important role in testing gravity theories since 1970s. Because radio timing of binary pulsars is very sensitive to changes in the orbital dynamics, small deviations from what GR predicts can be captured or constrained. In this sense, the gravity sector in the standard-model extension was constrained tightly with a set of pulsar systems. Moreover, compact objects like pulsars are possible to develop nonperturbative deviations from GR in some specific alternative gravity theories, thus radio pulsars also provide rather unique testbeds in the strong-gravity regime.