An independent test on the local position invariance of gravity with the triple pulsar PSR J0337  +  1715. (8th August 2017)

• Record Type: Journal Article
• Authors: Shao, Lijing
• Is Part Of: Classical and quantum gravity. Volume 34:Number 17(2017:Sep.)
• Publication Date: 2017-08-08
• Subjects: gravitation -- pulsar -- strong equivalence principle -- local position invariance; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/aa8124
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: We design a direct test of the l o c a l p o s i t i o n i n v a r i a n c e (LPI) in post-Newtonian gravity, using the timing observation of the triple pulsar, P S R J 0337 + 1715 . The test takes advantage of the large gravitational acceleration exerted by the outer white dwarf to the inner neutron star—white dwarf binary. Using machine-precision three-body simulations and dedicated Markov-chain Monte Carlo (MCMC) techniques with various sampling strategies and noise realizations, we estimate that the Whitehead's parameter could have already been limited to | ξ | ≲ 0.4 (95% CL), with the published timing data spanning from January 2012 to May 2013. The constraint is still orders of magnitude looser than the best limit, yet it is able to independently falsify Whitehead's gravity theory where ξ = 1 . In addition, the new test is immune to extra assumptions and involves full dynamics of a three-body system with a strongly self-gravitating neutron star.