Neutron Star in Covariant $f(Q)$ gravity
Assuming static and spherically symmetric stars with perfect fluid matter, we used realistic equations of state to study neutron stars in covariant $f(Q)$ gravity. The structure profiles and properties of neutron stars such as mass, radius and compactness are obtained through numerical methods using quadratic, exponential, and logarithmic $f(Q)$ models. The results indicate that nonmetricity affects the interior profile deviations of the star, which in turn influence the properties of stars, as illustrated in the mass-radius relation diagram. This effect allows the star to accommodate either more or less matter compared to GR, resulting in a different total mass. For the quadratic model, we cannot generate larger masses, whereas the other two models can give consistent results for both smaller and larger masses of the observed stars. By tuning model parameters, we obtain $\mathcal{M}-\mathcal{R}$ diagrams that are compatible with observational constraints from NICER and LIGO.