Nuclear Matter for compact stars and its properties

TL;DR

This paper develops a nucleonic equation of state for neutron star matter that aligns with observed mass-radius data and rules out exotic matter models, supporting the existence of massive neutron stars around 2 solar masses.

Contribution

It introduces a density-dependent effective NN interaction-based EoS that satisfies observational constraints and excludes exotic matter models for neutron stars.

Findings

EoS matches observed neutron star mass-radius data

Maximum neutron star mass around 1.95 solar masses

Excludes exotic matter models predicting lower maximum masses

Abstract

A pure nucleonic equation of state (EoS) for beta equilibrated charge neutral neutron star (NS) matter is determined using density dependent effective NN interaction. This EoS is found to satisfy both the constraints from the observed mass-radius of neutron stars and flow data from heavy-ion collisions. Recent observations of the binary millisecond pulsar J1614-2230 by P. B. Demorest et al. [1] suggest that the masses lie within (1.97\pm 0.04) M_\odot (M_\odot, solar mass). Most EoS involving exotic matter, such as kaon condensates or hyperons, tend to predict maximum masses well below 2.0M_\odot and are therefore ruled out. We are able to reproduce the measured mass-radius relationship for rotating and static NS. We ensure that the star rotating not faster than the frequency limited by r-mode instability gives the maximum mass about 1.95M_\odot with radius about 10 kilometer.