Effect of $f(R,T)$ theory of gravity on the properties of strange quark stars

Abstract: In this study, we investigate strange quark stars within the framework of modified $f(R,T)$ gravity, where $R$ represents the Ricci scalar and $T$ denotes the trace of the energy-momentum tensor, specifically defined as $ f(R,T) = R + 2\chi T $. The equation of state is obtained with the different forms of the MIT bag model and quark mass model with medium effects and self-consistent thermodynamical treatment. We find that negative values of $\chi$ significantly increase both the mass and radius of the quark star. The inclusion of $\chi$ helps to satisfy recent the astrophysical constraints on the mass-radius relationship. We have also constrained the values of $\chi$ for each EoS, based on the observed maximum mass and corresponding radius, demonstrating that the inclusion of this parameter helps to address the challenges posed by both the GW190814 event and NICER observations of PSR J0030+0451. We also observe that the inclusion of $f(R,T)$ gravity leads to an increase in both the maximum mass, by about $ (0.23- 0.27)~M_{\odot}$, and the corresponding radius, by approximately (1.5-2.0)~\text{km}, depending on the chosen equation of state.