Neutron Stars with realistic EoS in f(R) theories of gravity

TL;DR

This paper investigates neutron star structures within specific f(R) gravity models using realistic equations of state, analyzing mass-radius relations and constraining model parameters through astrophysical observations.

Contribution

It introduces a detailed analysis of neutron star properties in perturbative f(R) gravity with realistic EoS, providing new constraints on the gravity modification parameter.

Findings

Mass-radius relations fit within observational limits in GR.

Realistic EoS constrain the perturbative parameter α.

Strange particles in NS cores influence the EoS and constraints.

Abstract

In this paper, we examine neutron star structure in perturbative $f(R)$ gravity models with realistic equation of state. We obtain mass-radius relations in two gravity models of the form $f_{1}(R)=R+ \alpha R(e^{-R/R_0}-1)$ and $f_{2}(R)=R+\alpha R^2$. For this purpose, we consider NS with several nucleonic as well as strange EoSs generated in the framework of relativistic mean field models. The strange particles in the core of NS are in the form of $\Lambda$ hyperons and quarks, in addition to the nucleons and leptons. The M-R relation of the chosen EoSs lies well within the observational limit in the case of GR. We show that these EoSs provide the most stringent constraint on the perturbative parameter $\alpha$ and therefore can be considered as important experimental probe for modified gravity at astrophysical level.