Stability of Neutron Star and Cosmological Constant

TL;DR

This paper investigates how a non-zero cosmological constant affects the pressure, stability, and mass-radius relationship of neutron stars, confirming the stability theorem's applicability and highlighting significant changes for certain $\

Contribution

It extends neutron star models by incorporating a cosmological constant and analyzes its impact on stability and structural properties.

Findings

The stability theorem remains valid with a cosmological constant.

A significant change in mass-radius relation occurs for $\\Lambda \\geq 10^{-11} \\rm m^{-2}$.

The cosmological constant influences neutron star mass and size predictions.

Abstract

We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our analysis shows that the theorem used to assess the stability of stellar structures at equilibrium remains applicable to neutron stars even when a cosmological constant is considered. We further numerically solve the stellar structure equations and determine the mass of neutron star using different equations of state (EOS). Moreover, we observe that the value of the cosmological constant ($\Lambda \geq 10^{-11} \rm m^{-2}$) causes a significant change in the mass-radius relationship of neutron stars.