Mass-radius relation, moment of inertia, and tidal love numbers of anisotropic neutron stars in f (R,T) gravity

Abstract

The mass-radius relation, moment of inertia, and tidal love numbers of anisotropic neutron stars (NSs) have been investigated in $f(R,T)$ gravity by imposing two equations of state (EoS). We use the simplest form $f(R,T)=R+2\beta T$ model and adopt the anisotropy approach called Horvat model. To examine the viability of our calculations, we utilize the constraints from GW170817 and GW190814 observations. Moreover, we consider three values of $\beta$, i.e. $\beta=0$, $\beta=-0.01$, $\beta=-0.02$ and four anisotropy parameters $\alpha$, i.e. $\alpha=-0.12$, $\alpha=-0.06$, $\alpha=0.06$, $\alpha=0.12$. Our findings suggest that all physical quantities depend on both parameters $\alpha$ and $\beta$. Nevertheless, the impact of $\alpha$ is much more significant than $\beta$. The calculation of masses satisfy each used constraints for specific values of $\alpha$ and $\beta$. In the case of the moment of inertia, the results are compatible with the constraint obtained from radio observation of heavy pulsar. On the other hand, the tidal deformability of the NSs composed of one EoS satisfy the GW170817 constraint while the NSs composed of the other one EoS are too small. These small numbers can be interpreted as the property of secondary object observed in GW190814. As a result, our theoretical investigation of NSs constructed with two EoS can be NSs candidates for GW170817 and GW190814, respectively.