Effects of High Density Phase Transitions on Neutron Star Dynamics

TL;DR

This paper investigates how a generic first order phase transition at extreme densities affects neutron star behavior and potential observable signals in gravitational waves and electromagnetic emissions.

Contribution

It introduces a model-independent approach using a piecewise polytropic equation of state to study phase transition effects on neutron star dynamics.

Findings

Phase transitions influence neutron star oscillations and stability.

Observable gravitational wave signatures can indicate phase transition occurrence.

Magnetic fields modulate the dynamical effects of phase transitions.

Abstract

Various theoretical arguments motivate an expectation of a phase transition in matter at extreme densities above nuclear density, accompanied by hopes that gravitational wave observations may reveal the properties of such a transition. Instead of adopting a particular theory, we consider here a generic form of first order phase transition using a piecewise polytropic equation of state, and evolve both isolated neutron stars and neutron star binaries, including unequal mass binaries and, in some cases, magnetic field, looking at dynamical effects. Of particular interest are effects that may be observable either via gravitational waves or electromagnetic observations.