Neutron Stars in f(R) Gravity with Perturbative Constraints

TL;DR

This paper explores how f(R) gravity theories with perturbative constraints alter neutron star structures, showing that surface observations alone cannot distinguish these theories from standard models, but interior cooling observations can.

Contribution

It derives modified TOV equations in f(R) gravity with perturbative constraints and analyzes their impact on neutron star properties and observational constraints.

Findings

Surface phenomena cannot distinguish modified gravity from standard models.

Neutron-star cooling observations can constrain f(R) gravity parameters.

Modifications affect neutron star masses and radii.

Abstract

We study the structure of neutron stars in f(R) gravity theories with perturbative constraints. We derive the modified Tolman-Oppenheimer-Volkov equations and solve them for a polytropic equation of state. We investigate the resulting modifications to the masses and radii of neutron stars and show that observations of surface phenomena alone cannot break the degeneracy between altering the theory of gravity versus choosing a different equation of state of neutron-star matter. On the other hand, observations of neutron-star cooling, which depends on the density of matter at the stellar interior, can place significant constraints on the parameters of the theory.