Anisotropic Compact Objects in Modified $f(R,T)$ gravity

TL;DR

This paper develops models of anisotropic neutron stars within a modified gravity framework, analyzing their physical properties, stability, and predicting stellar radii and equations of state without assuming an initial equation of state.

Contribution

It introduces a new class of anisotropic stellar models in $f(R,T)$ gravity, exploring their stability and physical properties without predefining an equation of state.

Findings

Models can accommodate more massive stars with negative $\\chi$

Predicted stellar radii and EoS depend on the coupling constant

Models satisfy physical acceptability and stability criteria

Abstract

We obtain a class of anisotropic spherically symmetric relativistic solutions of compact objects in hydrostatic equilibrium in the $f(R,T) =R+2\chi T$ modified gravity, where $R$ is the Ricci scalar, $T$ is the trace of the energy momentum tensor and $\chi$ is a dimensionless coupling parameter. The matter Lagrangian is $L_{m}=- \frac{1}{3}(2p_{t}+p_{r})$, where $p_r$ and $p_t$ represents the radial and tangential pressures. Compact objects with dense nuclear matter is expected to be anisotropic. Stellar models are constructed for anisotropic neutron stars working in the modified Finch-Skea (FS) ansatz without preassuming an equation of state. The stellar models are investigate plotting physical quantities like energy density, anisotropy parameter, radial and tangential pressures in all particular cases. The stability of stellar models are checked using the causality conditions and adiabatic index. Using the observed mass of a compact star we obtain stellar models that predicts the radius of the star and EoS for matter inside the compact objects with different values of gravitational coupling constant $\chi$. It is also found that a more massive star can be accommodated with $\chi <0$. The stellar models obtained here obey the physical acceptability criteria which show consistency for a class of stable compact objects in modified $f(R, T)$ gravity.