Constraining the neutron star equation of state by including the isoscalar-vector and isovector-vector coupling using the Bayesian analysis

TL;DR

This paper uses Bayesian analysis to constrain the neutron star equation of state by incorporating isoscalar-vector and isovector-vector couplings, aligning nuclear physics models with astrophysical observations.

Contribution

It introduces a Bayesian framework to include specific vector couplings in the relativistic mean field model for neutron star matter, improving constraints on the equation of state.

Findings

Non-zero vector couplings stiffen the EoS.

Produced neutron stars > 2.5 solar masses.

All EoS satisfy nuclear saturation properties.

Abstract

We constrain the nuclear matter equation of state within the relativistic mean field model by including the isoscalar-vector and isovector-vector coupling term at a fundamental level using the Bayesian analysis. We used the nuclear saturation properties and recent astrophysical observations to constrain the dense matter equation of state. We obtained about 20000 sets of equations of states out of sampling about 60 millions sets of equations of states. All 20000 equations of states satisfy nuclear matter saturation properties at saturation densities and produces high mass neutron stars. In our findings, we find that the non-zero value of isoscalar-vector and isovector-vector coupling parameter and negative value of sigma meson self-coupling stiffen the equation of state. Our sets of equations of state produces neutron stars of mass larger than 2.5 M$_{\odot}$ to include the recent gravitational waves observation GW190419.