Non-perturbative and self-consistent models of neutron stars in<i>R</i>-squared gravity

Abstract

In the present paper we investigate non-perturbatively and self-consistently\nthe structure of neutron stars in $R$-squared gravity by simultaneously solving\nthe interior and exterior problem. The mass-radius relations are obtained for\nseveral equations of state and for wide range of the $R$-squared gravity\nparameter $a$. Even though the deviation from general relativity for nonzero\nvalues of $a$ can be large, they are still comparable with the variations due\nto different modern realistic equations of state. That is why the current\nobservations of the neutron star masses and radii alone can not put constraints\non the value of the parameter $a$. We also compare our results with those\nobtained within the perturbative method and we discuss the differences between\nthem.\n