PSR J0337+1715: an appropriate laboratory for testing the Nordtvedt effect

TL;DR

This paper proposes that the pulsar PSR J0337+1715 in a triple system is an excellent natural laboratory for testing the strong equivalence principle, providing improved constraints on the Nordtvedt parameter through orbital analysis.

Contribution

It introduces a new method to estimate the Nordtvedt parameter using the triple system's orbital data, achieving tighter bounds than previous tests.

Findings

Estimated Nordtvedt parameter $ ext{<}10^{-4}$ from orbital polarization.

Potential to constrain $ ext{η}_ ext{N}$ to $10^{-7}$ with future data.

Highlights the importance of precise timing measurements for gravity tests.

Abstract

Highly accurate binary-pulsar timing plays an important role in test of General Relativity. In this Letter, we argue that PSR J0337+1715, a milli-second pulsar in a stellar triple system, could be a very good laboratory for testing the strong equivalence principle (SEP). From the reported orbital parameters of this triple system, we give an uplimited estimation of the Nordtvedt parameter $\eta_\text{N} < 10^{-4}$ based on the orbital polarization calculation. This result is slightly better than the existed ones. In addition, if based on the observed uncertain value of inner orbital eccentricity, we even can obtain $\eta_\text{N}$ up to $10^{-7}$, which needs to be confirmed in future. However, more rigorous and accurate measurement of the Nordtvedt effect should be taken from more timing data of PSR J0337+1715.