Testing Lorentz violation with binary pulsars: constraints on standard model extension

Under the standard model extension (SME) framework, Lorentz invariance is tested in five binary pulsars: PSR J0737-3039, PSR B1534+12, PSR J1756-2251, PSR B1913+16 and PSR B2127+11C. By analyzing the advance of periastron, we obtain the constraints on a dimensionless combination of SME parameters that is sensitive to timing observations. The results imply no evidence for the break of Lorentz invariance at $10^{-10}$ level, one order of magnitude larger than previous estimation.

💡 Research Summary

The paper investigates possible violations of Lorentz invariance within the framework of the Standard‑Model Extension (SME) by exploiting high‑precision timing data from five well‑studied binary pulsars: PSR J0737‑3039, PSR B1534+12, PSR J1756‑2251, PSR B1913+16, and PSR B2127+11C. In the SME, all conceivable Lorentz‑violating operators are added to the Lagrangian, and in the gravitational sector the dominant effects at the first post‑Newtonian (1PN) order are encoded in a dimensionless, symmetric, traceless tensor (\bar{s}^{\mu\nu}). The authors focus on a particular linear combination of the components of (\bar{s}^{\mu\nu}) that directly modifies the rate of periastron advance, (\dot\omega), a quantity that can be measured with exquisite accuracy in pulsar timing experiments.

The theoretical development begins by writing the 1PN equations of motion for a binary system in the presence of SME corrections. The periastron advance acquires an extra term, \