New tests of local Lorentz invariance and local position invariance of gravity with pulsars

New tests are proposed to constrain possible deviations from local Lorentz invariance and local position invariance in the gravity sector. By using precise timing results of two binary pulsars, i.e., PSRs J1012+5307 and J1738+0333, we are able to constrain (strong-field) parametrized post-Newtonian parameters $\hat{\alpha}_1$, $\hat{\alpha}_2$, $\hat{\xi}$ to high precision, among which, $|\hat{\xi}| < 3.1\times10^{-4}$ (95% C.L.) is reported here for the first time.
Comment: 3 pages, 1 figure; submitted to Proceedings of the Thirteenth Marcel Grossmann Meeting, (eds.) Kjell Rosquist, Robert T Jantzen, Remo Ruffini