One pulsar, two white dwarfs, and a planet confirming the strong equivalence principle

Guillaume Voisin (1) , G Luth , I Cognard , P Freire , N Wex , L Guillemot , G Desvignes , M Kramer , G Theureau , M Saillenfest

1 LUTH (UMR_8102) - Laboratoire Univers et Théories

The strong equivalence principle is a cornerstone of general relativity, tested with exquisite accuracy in the Solar system. However, tests in the strong-field regime require a compact object. Currently, PSR J0337+1715 is the unique millisecond pulsar found in a triple stellar system, orbiting two white dwarfs within an area comparable to the orbit of the Earth. This configuration offers the opportunity for a dramatic improvement over previous tests, provided that accurate and regular timing of the pulsar can be achieved. This also requires the development of a new timing model solving numerically the relativistic three-body problem with great accuracy. We report on the analysis of the high-quality dataset gathered on PSR J0337+1715 by the Nançay radiotelescope over the past 8 years. In particular, I will show how we could obtain the most stringent limit to-date on a potential violation of the strong equivalent principle in the strong field regime. I will also introduce preliminary resuts showing that the presence of a small planet in the system may explain a tiny residual signal so far unaccounted for, which if confirmed would make this system exceptionally rich.

Mots clés: PSR J0337+1715; Strong equivalence principle; Pulsar timing; PSR J0337+1715; PSR J0337+1715

Domaines: Relativité Générale et Cosmologie Quantique [gr-qc]; Phénomènes cosmiques de haute energie [astro-ph.HE]

Guillaume Voisin, G Luth, I Cognard, P Freire, N Wex, et al.. One pulsar, two white dwarfs, and a planet confirming the strong equivalence principle. 2022 Gravitation session of the 56th Rencontres de Moriond, Jan 2022, La Thuile, Italy. ⟨hal-03609770⟩