Calculation of the transport coefficients in neutron star

TL;DR

This paper calculates shear viscosity and thermal conductivity in neutron star cores using relativistic kinetic theory, revealing neutron and electron dominance respectively, with results depending on density and temperature.

Contribution

It introduces a modified BUU equation approach with relativistic mean field models to compute transport coefficients in neutron star matter.

Findings

Shear viscosity mainly influenced by neutrons.

Thermal conductivity primarily dominated by electrons.

Transport coefficients vary with density and temperature.

Abstract

In this work, we have calculated the transport coefficients: shear viscosity and thermal conductivity inside the neutron star core. Our calculation is based on the relativistic kinetic theory approach using a modified BUU equation for quasi-particles whose mass and the chemical-potential and thus in turn the Fermi surface varies with the baryonic density $\rho_{B}$ and the temperature of the medium, and we have used the relaxation time approximation. For the description of the hadronic matter inside the neutron star, we consider the relativistic mean field model with three different kinds of parameterizations. We have found that the shear viscosity is predominantly influenced by neutrons, while thermal conductivity is primarily dominated by electrons.