Dynamical evolution of dark matter admixed neutron stars

TL;DR

This paper presents the first dynamical evolution of dark matter admixed neutron stars, analyzing their stability, oscillations, and formation through advanced numerical simulations.

Contribution

It introduces a new method to simulate the dynamical behavior of neutron stars containing fermionic dark matter, including equations of motion and numerical techniques.

Findings

Demonstrates nonlinear stability of dark matter admixed neutron stars

Calculates radial oscillation frequencies for these stars

Models the dynamical formation process of such systems

Abstract

We dynamically evolve for the first time dark matter admixed neutron stars with fermionic dark matter. These systems are mixtures of the ordinary nuclear matter of a neutron star and dark matter. To perform our dynamical evolutions, we derive the equations of motion, in conservation form, for spherically symmetric systems with an arbitrary number of perfect fluids. Using finite volume and high-resolution shock-capturing methods, we dynamically evolve the two-fluid case, with the first fluid modeling ordinary matter and the second fluid modeling dark matter. We use our dynamical solutions to study nonlinear stability, radial oscillation frequencies, and a dynamical formation process.