Rapidly rotating neutron stars in $f(R,T)$ gravity

TL;DR

This paper investigates how $f(R,T)$ gravity affects the physical properties of rapidly rotating neutron stars, revealing significant deviations from general relativity in mass, radius, and other characteristics.

Contribution

It introduces the basic equations for neutron stars in $f(R,T)$ gravity and analyzes their physical properties across different rotation regimes, highlighting notable modifications from GR.

Findings

$f(R,T)$ gravity increases neutron star mass and radius at sub-Keplerian rotation speeds.

Physical quantities like moments of inertia and compactness are significantly affected.

Results suggest observable differences from general relativity in rapidly rotating neutron stars.

Abstract

In this work, we study the influence of $f(R,T)$ gravity on rapidly rotating neutron stars. First we discuss the main aspects of this modified theory of gravity where the gravitational Lagrangian is an arbitrary function of the Ricci scalar $R$ and of the trace of the energy-momentum tensor $T$. Then we present the basic equations for neutron stars including the equations of state used in the present work to describe the hadronic matter. Some physical quantities of interest are calculated such as mass-radius relations, moments of inertia, angular momentum, and compactness. By considering four different rotation regimes, we obtain results that indicate substantial modifications in the physical properties of neutron stars in $f(R,T)$ gravity when compared to those in the context of general relativity. In particular, the mass-radius relation for sequences of stars indicates that $f(R,T)$ gravity increases the mass and the equatorial radius of the neutron stars for stars rotating with an angular velocity smaller than Kepler limit.