Constraining Energy-Momentum-Squared Gravity by binary pulsar observations

Abstract

In this paper, we introduce the post-Minkowskian approximation of Energy-Momentum-Squared Gravity (EMSG). This approximation is used to study the gravitational energy flux in the context of EMSG. As an application of our results, we investigate the EMSG effect on the first time derivative of the orbital period of the binary pulsars. Utilizing this post-Keplerian parameter, the free parameter of the EMSG theory, $f_0'$, is estimated for six known binary pulsars. Taking the binaries that have the most accurate observations, it turns out that $-6\times 10^{-37}\text{m}\,\text{s}^2\text{kg}^{-1}<f_0'<+10^{-36}\text{m}\,\text{s}^2\text{kg}^{-1}$. This bound is in agreement with the precedent studies.