Impact of charge on the stability of pulsar SAX J1748.9-2021 in modified symmetric teleparallel gravity

Abstract

In this paper, we explore the effect of charge on the stability of pulsar star SAX J1748.9-2021 in $f\left(Q\right)$ gravity, where $Q$ represents non-metricity. For this purpose, we apply the Krori–Barua metric ansatz with anisotropic fluid and use a linear $f\left(Q\right)$ model $f\left(Q\right)=\zeta Q$, where $\zeta$ is a non-zero constant. We derive exact relativistic solutions of the corresponding field equations. Furthermore, we study its geometric and physical properties through astrophysical observations from the pulsar SAX J1748.9-2021, which is found in X-ray binary systems within globular clusters. We examine features like anisotropic pressure, the mass–radius relationship, redshift, the Zeldovich condition, energy and causality conditions, the adiabatic index, the Tolman–Oppenheimer–Volkoff equation, the equation of state parameter and compactness. Our findings align with the observational data which indicate that the pulsar SAX J1748.9-2021 is viable and stable under this modified theory of gravity.